The slowness or difficulty with, which atmospheres, which differ but little in kind or in density, unite with each other, appears not only from the experiment of Mr. Canton above related, but also from the repeated smaller shocks, which may be taken from a charged coated jar after the first or principal discharge, if the conducting medium has not been quickly removed, as is also mentioned above.
Hence those atmospheres of either kind of electric matter, which differ but very little from each other in kind or quantity, require the most perfect conductors to cause them to unite. Thus it appears by Mr. Bennet's doubler, as mentioned in the Preliminary Proposition, No. VI. that the natural adhesive atmosphere round silver contains more vitreous electricity than that naturally round zinc; but when thin plates of these metals, each about an ounce in weight, are laid on each other, or moderately pressed together, their atmospheres do not unite. For metallic plates, which when laid on each other, do not adhere, cannot be said to be in real contact, of which their not adhering is a proof; and in consequence a thin plate of air, or of their own repulsive ethers exists between them.
Hence when two plates of zinc and silver are thus brought in to the vicinity of each other, the plate of air between them, as they are not in adhesive contact, becomes like a charged coated jar; and if these two metallic plates are touched by your dry hands, they do not unite their electricities, as the dry cuticle is not a sufficiently good conductor; but if one of the metals be put above, and another under the tongue, the saliva and moist mucous membrane, muscular fibres, and nerves, supply so good a conductor, that this very minute electric shock is produced, and a kind of pungent taste is perceived.
When a plate or pencil of silver is put between the upper lip and the gum, and a plate or pencil of zinc under the tongue, a sensation of light is perceived in the eyes, as often as the exterior extremities of these metals are brought into contact; which is owing in like manner to the discharge of a very minute electric shock, which would not have been produced but by the intervention of such good conductors as moist membranes, muscular fibres, and nerves.
In this situation, a sensation of light is produced in the eyes; which seems to show, that these ethers pass through nerves more easily, than through muscular flesh simply; since the passage of them through the retina of the eyes from the upper gum to the parts beneath the tongue is a more distant one, than would otherwise appear necessary. It is not so easy to give the sensation of light in the eyes by passing a small shock of artificially accumulated electricity through, the eyes (though this may, I believe, be done) because this artificialaccumulated electricity, as it passes with greater velocity than the spontaneous accumulations of it, will readily permeate the muscles or other moist parts of animal bodies; whereas the spontaneous accumulations of electricity seem to require the best of all conductors, as animal nerves, to facilitate their passage.
4. In the Galvanic pile of Volta this electric shock becomes so much increased, as to pass by less perfect conductors, and to give shocks to the arms of the conducting person, if the cuticle of his hands be moistened, and even to show sparks like the coated jar; which appears to be effected in this manner. When a plate of silver is laid horizontally on a plate of zinc, the plate of air between them becomes charged like a coated jar; as the silver, naturally possessing more vitreous electric ether, repels the vitreous ether, which the zinc possesses in less quantity, and attracts the resinous ether of the zinc. Whence the inferior surface of the plate of zinc abounds now with vitreous ether, and its upper surface with resinous ether. Beneath this pair of plates lay a cloth moistened with water, or with some better conductor, as salt and water, or a slight acid mixed with water, or volatile alcali of ammoniac mixed with water, and this vitreous electric ether on the lower surface of the zinc plate will be given to the second silver plate which lies beneath it; and thus this second silver plate will possess not only its own natural vitreous atmosphere, which was denser or in greater quantity than that of the zinc plate next beneath it, but now acquires an addition of vitreous ether from the zinc plate above it, conducted to it through the moist cloth.
This then will repel more vitreous ether from the second zinc plate into the third silver one; and so on till the plates of air between the zincs and silvers are all charged, and each stronger and stronger, as they descend in the pile.
If the reader still prefers the Franklinian theory of positive and negative electricity, he will please to put the word positive for vitreous, and negative for resinous, and he will find the theory of the Galvanic pile equally thus accounted for.
5. When a Galvanic pile is thus placed, and a communication between the two ends of it is made by wires, so that the electric shocks pass through water, the water becomes decomposed in some measure,and oxygen is liberated from it at the point of one wire, and hydrogen at the point of the other; and this though a syphon of water be interposed between them. This curious circumstance seems to evince the existence of two electric ethers, which enter the water at different ends of the syphon, and have chemical affinities to the component parts of it; the resinous ether sets at liberty the hydrogen at one end, and the vitreous ether the oxygen at the other end of the conducting medium.
Hence it must appear, that the longer the Galvanic pile, or the greater the number of the alternate pieces of silver and zinc that it consists of, the stronger will be the Galvanic shock; but there is another circumstance, difficult to explain, which is the perpetual decomposition of water by the Galvanic pile; when water is made the conducting medium between the two extremities of the pile.
As no conductors of electricity are absolutely perfect, there must be produced a certain accumulation of vitreous ether on one side of each charged plate of the Galvanic pile, and of resinous ether on the other side of it, before the discharge takes place, even though the conducting medium be in apparent contact. When the discharge does take place, the whole of the accumulated electricity explodes and vanishes; and then an instant of time is required for the silver and zinc again to attract from the air, or other bodies in their vicinity, their spontaneous natural atmospheres, and then another discharge ensues; and so repeatedly and perpetually till the surface of one of the metallic plates becomes so much oxydated or calcined, that it ceases to act.
Hence a perpetual motion may be said to be produced, with an incessant decomposition of water into the two gasses of oxygen and hydrogen; which must probably be constantly proceeding on all moist Surfaces, where a chain of electric conductors exists, surrounded with different proportions of the two electric ethers. Whence the ceaseless liberation of oxygen from the water has oxydated or calcined the ores of metals near the surface of the earth, as of manganese, of zinc into lapis calaminaris, of iron into various ochres, and other calciform ores. From this source also the corrosion of some metals may be traced, when they are immersed in water in the vicinity of eachother, as when the copper sheathing of ships was held on by iron nails. And hence another great operation of nature is probably produced, I mean the restoration of oxygen to the atmosphere from the surface of the earth in dewy mornings, as well as from the perspiration of vegetable leaves; which atmospheric oxygen is hourly destructible by the respiration of animals and plants, by combustion, and by other oxydations.
6. The combination of the electric ethers with metallic bodies, before mentioned appears from the Galvanic pile; since, according to the experiments of Mr. Davy, when an acid is mixed with the water placed between the alternate pairs of silver and zinc plates, a much greater electric shock is produced by the same pile; and an anonymous writer in the Phil. Magaz. No. 36, for May 1801, asserts, that when the intervening cloths or papers are moistened with pure alcali, as a solution of pure ammonia, the effect is greater than by any other material. It must here be observed, that both the acid and the alcaline solution, or common salt and water, and even water alone, in these experiments much erodes the plates of zinc, and somewhat tarnishes those of silver. Whence it would appear, that as by the repeated explosions of the two electric ethers in the conducting water, both oxygen and hydrogen are liberated; the oxygen erodes the zinc plates, and thus increases the Galvanic shock by liberating their combined electric ethers: and that this erosion is much increased by a mixture either of acid or of volatile alcali with the water. Further experiments are wanting on this subject to show whether metallic bodies emit either or both of the electric ethers at the time of their solution or erosion in acids or in alcalies.
X.Of the two Magnetic Ethers.
1. Magnetism coincides with electricity in so many important points, that the existence of two magnetic ethers, as well as of two electric ones, becomes highly probable. We shall suppose, that in a common bar of iron or steel the two magnetic ethers exist intermixed or in their neutral state; which for the greater ease of speaking ofthem may be called arctic ether and antarctic ether; and in this state like the two electric fluids they are not cognizable by our senses of experiments.
When these two magnetic ethers are separated from each other, and the arctic ether is accumulated on one end of an iron or steel bar, which is then called the north pole of the magnet, and the antarctic ether is accumulated on the other end of the bar, and is then termed the south pole of the magnet; they become capable of attracting other pieces of iron or steel, and are thus cognizable by experiments.
It seems probable, that it is not the magnetic ether itself which attracts or repels particles of iron, but that an attractive and repulsive ether attends the magnetic ethers, as was shown to attend the electric ones in No. II. 9. of this Note; because magnetism does not pass through other bodies, as it does not escape from magnetised steel when in contact with other bodies; just as the electric fluids do not pass through glass, but the attractive and repellent ethers, which attend both the magnetic and electric ethers, pass through all bodies.
2. The prominent articles of analogical coincidence between magnetism and electricity are first, that when one end of an iron bar possesses an accumulation of arctic magnetic ether, or northern polarity; the other end possesses an accumulation of antarctic magnetic ether, or southern polarity; in the same manner as when vitreous electric ether is accumulated on one side of a coated glass jar, resinous electric ether becomes accumulated on the other side of it; as the vitreous and resinous ethers strongly attract each other, and strongly repel the ethers of the same denomination, but are prevented from intermixing by the glass plane between them; so the arctic and antarctic ethers attract each other, and repel those of similar denomination, but are prevented from intermixing by the iron or steel being a bad conductor of them; they will, nevertheless, sooner combine, when the bar is of soft iron, than when it is of hardened steel; and then they slowly combine without explosion, that is, without emitting heat and light like the electric ethers, and therefore resemble a mixture of oxygen and pure ammonia; which unite silently producing a neutral fluid without emitting any other fluids previously combined with them.
Secondly, If the north pole of a magnetic bar be approached near to the eye of a sewing needle, the arctic ether of the magnet attracts the antarctic ether, which resides in the needle towards the eye of it, and repels the arctic ether, which resides in the needle towards the point, precisely in the same manner as occurs in presenting an electrised, glass tube, or a rubbed stick of sealing wax to one extremity of two skewers insulated horizontally on wine-glasses in the experiment ascribed to Mr. Canton, and described in No. IX. 1, of this Additional Note, and also so exactly resembles the method of producing a separation and consequent accumulation of the two electric ethers by pressing a cushion on glass or on sealing wax, described in No. 4 of this Note, that their analogy is evidently apparent.
Thirdly, When much accumulated electricity is approached to one end of a long glass tube by a charged prime conductor, there will exist many divisions of the vitreous and resinous electricity alternately; as the vitreous ether attracts the resinous ether from a certain distance on the surface of the glass tube, and repels the vitreous ether; but, as this surface is a bad conductor, these reciprocal attractions and repulsions do not extend very far along it, but cease and recur in various parts of it. Exactly similar to this, when a magnetic bar is approximated to the end of a common bar of iron or steel, as described in Mr. Cavallo's valuable Treatise on Magnetism; the arctic ether of the north pole of the magnetic bar attracts the antarctic ether of the bar of common iron towards the end in contact, and repels the arctic ether; but, as iron and steel are as bad conductors of magnetism, as glass is of electricity, this accumulation of arctic ether extends but a little way, and then there exists an accumulation of antarctic ether; and thus reciprocally in three or four divisions of the bar, which now becomes magnetised, as the glass tube became electrised.
Another striking feature, which shows the sisterhood of electricity and magnetism, consists in the origin of both of them from the earth, or common mass of matter. The eduction of electricity from the earth is shown by an insulated cushion soon ceasing to supply either the vitreous or resinous ether to the whirling globe of glass or of sulphur; the eduction of magnetism from the earth appears from thefollowing experiment: if a bar of iron be set upright on the earth in this part of the world, it becomes in a short time magnetical; the lower end possessing northern polarity, or arctic ether, and the higher end in consequence possessing southern polarity or antarctic ether; which may be well explained, if we suppose with Mr. Cavallo, that the earth itself is one great magnet, with its southern polarity or antarctic ether at the northern end of its axis; and, in consequence, that it attracts the arctic ether of the iron bar into that end of it which touches the earth, and repels the antarctic ether of the iron bar to the other end of it, exactly the same as when the southern pole of an artificial magnet is brought into contact with one end of a sewing needle.
3. The magnetic and electric ethers agree in the characters above mentioned, and perhaps in many others, but differ in the following ones. The electric ethers pass readily through metallic, aqueous, and carbonic bodies, but do not permeate vitreous or resinous ones; though on the surfaces of these they are capable of adhering, and of being accumulated by the approach or contact of other bodies; while the magnetic ethers will not permeate any bodies, and are capable of being accumulated only on iron and steel by the approach or contact of natural or artificial magnets, or of the earth; at the same time the attractive and repulsive powers both of the magnetic and electric ethers will act through all bodies, like those of gravitation and heat.
Secondly, The two electric ethers rush into combination, when they can approach each other, after having been separated and condensed, and produce a violent explosion emitting the heat and light, which were previously combined with them; whereas the two magnetic ethers slowly combine, after having been separated and accumulated on the opposite ends of a soft iron bar, and without emitting heat and light produce a neutral mixture, which, like the electric combination, ceases to be cognizable by our senses or experiments.
Thirdly, The wonderful property of the magnetic ethers, when separately accumulated on the ends of a needle, endeavouring to approach the two opposite poles of the earth; nothing similar to which has been observed in the electric ethers.
From these strict analogies between electricity and magnetism,we may conclude that the latter consists of two ethers as well as the former; and that they both, when separated by art or nature, combine by chemical affinity when they approach, the one exploding, and then consisting of a residuum after having emitted heat and light; and the other producing simply a neutralised fluid by their union.
XI.Conclusion.
1. When two fluids are diffused together without undergoing any change of their chemical properties, they are said simply to be mixed, and not combined; as milk and water when poured together, or as oxygen and azote in the common atmosphere. So when salt or sugar is diffused in water, it is termed solution, and not combination; as no change of their chemical properties succeeds.
But when an acid is mixed with a pure alcali a combination is produced, and the mixture is said to become neutral, as it does not possess the chemical properties which either of the two ingredients possessed in their separate state, and is therefore similar to neither of them. But when a carbonated alcali, as mild salt of tartar, is mixed with a mineral acid, they presently combine as above, but now the carbonic acid flies forcibly away in the form of gas; this, therefore, may be termed a kind of explosion, but cannot properly be so called, as the ethereal fluids of heat and light are not principally emitted, but an aerial one or gas; which may probably acquire a small quantity of heat from the combining matters.
But when strong acid of nitre is poured upon charcoal in fine powder, or upon oil of cloves, a violent explosion ensues, and the ethereal matters of heat and light are emitted in great abundance, and are dissipated; while in the former instance the oxygen of the nitrous acid unites with the carbone forming carbonic acid gas, and the azote escapes in its gaseous form; which may be termed a residuum after the explosion, and may be confined in a proper apparatus, which the heat and light cannot; for the former, if its production be great and sudden, bursts the vessels, or otherwise it passes slowly throughthem; and the latter passes through transparent bodies, and combines with opake ones.
But where ethers only are concerned in an explosion, as the two electric ones, which are previously difficult to confine in vessels; the repulsive ethers of heat and light are given out; and what remains is a combination of the two electric ethers; which in this state are attracted by all bodies, and form atmospheres round them.
These combined electric atmospheres must possess less heat and light after their explosion; which they seem afterwards to acquire at the time they are again separated from each other, probably from the combined heat and combined light of the cushion and glass, or of the cushion and resin; by the contact of which they are separated; and not from the diffused heat of them; but no experiments have yet been made to ascertain this fact, this combination of the vitreous and resinous ethers may be esteemed the residuum after their explosion.
2. Hence the essence of explosion consists in two bodies, which are previously united with heat and light, so strongly attracting each other, as to set at liberty those two repulsive ethers; but it happens, that these explosive materials cannot generally be brought into each other's vicinity in a state of sufficient density; unless they are also previously combined with some other material beside the light and heat above spoken of: as in the nitrous acid, the oxygen is previously combined with azote; and is thus in a condensed state, before it is brought into the contact or vicinity of the carbone; there are however bodies which will slowly explode; or give out heat and light, without being previously combined with other bodies; as phosphorus in the common atmosphere, some dead fish in a certain degree of putridity, and some living insects probably by their respiration in transparent lungs, which is a kind of combustion.
But the two electric ethers are condensed by being brought into vicinity with each other with a nonconductor between them; and thus explode, violently as soon as they communicate, either by rupturing the interposed nonconductor, or by a metallic communication. This curious method of a previous condensation of the two explodingmatters, without either of them being combined with any other material except with the ethers of heat and light, distinguishes, this ethereal explosion from that of most other bodies; and seems to have been the cause, which prevented the ingenious Dr. Franklin, and others since his time, from ascribing the powerful effects of the electric battery, and of lightning in bursting trees, inflaming combustible materials, and fusing metals, to chemical explosion; which it resembles in every other circumstance, but in the manner of the previous condensation of the materials, so as violently to attract each other, and suddenly set at liberty the heat and light, with which one or both of them were combined.
3. This combination of vitreous and resinous electric ethers is again destroyed or weakened by the attractions of other bodies; as they separate intirely, or exist in different proportions, forming atmospheres round conducting and nonconducting bodies; and in this they resemble other combinations of matters; as oxygen and azote, when united in the production of nitrous acid, are again separated by carbone; which attracts the oxygen more powerfully, than that attracts the azote, with which it is combined.
This mode of again separating the combined electric ethers by pressing them, as they surround bodies in different proportions, into each other's atmospheres, as by the glass and cushion, has not been observed respecting the decomposition of other bodies; when their minute particles are brought so near together as to decompose each other; which has thence probably contributed to prevent this decomposition of the two combined electric ethers from being ascribed to chemical laws; but, as far as we know, the attractive and repulsive atmospheres round the minute particles of bodies in chemical operations may act in a similar manner; as the attractive and repulsive atmospheres, which accompany the electric ethers surrounding the larger masses of matter, and that hence both the electric and the chemical explosions are subject to the same laws, and also the decomposition again of those particles, which were combined in the act of explosion.
4. It is probable that this theory of electric and magnetic attractionsand repulsions, which so visibly exist in atmospheres round larger masses of matter, may be applied to explain the invisible attractions and repulsions of the minute particles of bodies in chemical combinations and decompositions, and also to give a clear idea of the attractions of the great masses of matter, which form the gravitations of the universe.
We are so accustomed to see bodies attract each other, when they are in absolute contact, as dew drops or particles of quicksilver forming themselves into spheres, as water rising in capillary tubes, the solution of salts and sugar in water, and the cohesion with which all hard bodies are held together, that we are not surprised at the attractions of bodies in contact with each other, but ascribe them to a law affecting all matter. In similar manner when two bodies in apparent contact repel each other, as oil thrown on water; or when heat converts ice into water and water into steam; or when one hard body in motion pushes another hard body out of its place; we feel no surprise, as these events so perpetually occur to us, but ascribe them as well as the attractions of bodies in contact with each other, to a general law of nature.
But when distant bodies appear to attract or repel each other, as we believe that nothing can act where it does not exist, we are struck with astonishment; which is owing to our not seeing the intermediate ethers, the existence of which is ascertained by the electric and magnetic facts above related.
From the facts and observations above mentioned electricity and magnetism consist each of them of two ethers, as the vitreous and resinous electric ethers, and the arctic and antarctic magnetic ethers. But as neither of the electric ethers will pass through glass or resin; and as neither of the magnetic ethers will pass through any bodies except iron; and yet the attractive and repulsive powers accompanying all these ethers permeate bodies of all kinds; it follows, that ethers more subtile than either the electric or magnetic ones attend those ethers forming atmospheres round them; as those electric and magnetic ethers themselves form atmospheres round other bodies.
This secondary atmosphere of the electric one appears to consistof two ethers, like the electric one which it surrounds: but these ethers are probably more subtile as they permeate all bodies; and when they unite by the reciprocal approach of the bodies, which they surround, they do not appear to emit heat and light, as the primary electric atmospheres do; and therefore they are simpler fluids, as they are not previously combined with heat and light. The secondary magnetic atmospheres are also probably more subtile or simple than the primary ones.
Hence we may suppose, that not only all the larger insulated masses of matter, but all the minute particles also, which constitute those masses, are surrounded by two ethereal fluids; which like the electric and magnetic ones attract each other forcibly, and as forcibly repel those of the same denomination; and at the same time strongly adhere to the bodies, which they surround. Secondly that these ethers are of the finer kind, like those secondary ones, which surround the primary electric and magnetic ethers; and that therefore they do not explode giving out heat and light when they unite, but simply combine, and become neutral; and lastly, that they surround different bodies in different proportions, as the vitreous and resinous electric ethers were shown to surround silver and zinc and many other metals in different proportions in No. IX. of this note.
5. For the greater ease of conversing on this subject, we shall call these two ethers, with which all bodies are surrounded, the masculine and the feminine ethers; and suppose them to possess the properties above mentioned. We should here however previously observe, that in chemical processes it is necessary, that the bodies, which are to combine or unite with each other, should be in a fluid state, and the particles in contact with each other; thus when salt is dissolving in water, the particles of salt unite with those of the water, which touch them; these particles of water become saturated, and thence attract some of the saline particles with less force; which are therefore attracted from them by those behind; and the first particles of water are again saturated from the solid salt; or in some similar processes the saturated combinations may subside or evaporate, as in the union of the two electric ethers, or in the explosion of gunpowder, and thus those in their vicinity may approach each other. This necessityof a liquid form for the purpose of combination appears in the lighting of gunpowder, as well as in all other combustion, the spark of fire applied dissolves the sulphur, and liquifies the combined heat; and by these means a fluidity succeeds, and the consequent attractions and repulsions, which form the explosion.
The whole mixed mass of matter, of which the earth is composed, we suppose to be surrounded and penetrated by the two ethers, but with a greater proportion of the masculine ether than of the feminine. When a stone is elevated above the surface of the earth, we suppose it also to be surrounded with an atmosphere of the two ethers, but with a greater proportion of the feminine than of the masculine, and that these ethers adhere strongly by cohesion both to the earth and to the stone elevated above it. Now the greater quantity of the masculine ether of the earth becomes in contact with the greater quantity of the feminine ether of the stone above it; which it powerfully attracts, and at the same time repels the less quantity of the masculine ether of the stone. The reciprocal attractions of these two fluids, if not restrained by counter attractions, bring them together as in chemical combination, and thus they bring together the solid bodies, which they reciprocally adhere to; if they be not immovable; which solid bodies, when brought into contact, cohere by their own reciprocal attractions, and hence the mysterious affair of distant attraction or gravitation becomes intelligible, and consonant to the chemical combinations of fluids.
To further elucidate these various attractions, if the patient reader be not already tired, he will please to attend to the following experiment: let a bit of sponge suspended on a silk line be moistened with a solution of pure alcali, and another similar piece of sponge be moistened with a weak acid, and suspended near the former; electrize one of them with vitreous ether, and the other with resinous ether; as they hang with a thin plate of glass between them: now as these two electric ethers appear to attract each other without intermixing; as neither of them can pass through glass; they must be themselves surrounded with secondary ethers, which pass through the glass, and attract each other, as they become in contact; as these secondary ethers adhere to the primary vitreous and resinous ethers, these primary ones are drawnby them into each other's vicinity by the attraction of cohesion, and become condensed on each side of the glass plane; and then when the glass plane is withdrawn, the two electric ethers being now in contact rush violently together, and draw along with them the pieces of moistened sponge, to which they adhere; and finally the acid and alcaline liquids being now brought into contact combine by their chemical affinity.
The repulsions of distant bodies are also explicable by this idea of their being surrounded with two ethers, which we have termed masculine and feminine for the ease of conversing about them; and have compared them to vitreous and resinous electricity, and to arctic and antarctic magnetism. As when two particles of matter, or two larger masses of it, are surrounded both with their masculine ethers, these ethers repel each other or refuse to intermix; and in consequence the bodies to which they adhere, recede from each other; as two cork-balls suspended near each other, and electrised both with vitreous or both with resinous ether, repel each other; or as the extremities of two needles magnetised both with arctic, or both with antarctic ether, repel each other; or as oil and water surrounded both with their masculine, or both with their feminine ethers, repel each other without touching; so light is believed to be reflected from a mirror without touching its surface, and to be bent towards the edge of a knife, or refracted by its approach from a rarer medium into a denser one, by the repulsive ether of the mirror, and the attractive ones of the knife-edge, and of the denser medium. Thus a polished tea-cup slips on the polished saucer probably without their actual contact with each other, till a few drops of water are interposed between them by capillary attraction, and prevent its sliding by their tenacity. And so, lastly, one hard body in motion pushes another hard body out of its place by their repulsive ethers without being in contact; as appears from their not adhering to each other, which all bodies in real contact are believed to do. Whence also may be inferred the reason why bodies have been supposed to repel at one distance and attract at another, because they attract when their particles are in contact with each other, and either attract or repelwhen at a distance by the intervention of their attractive or repulsive ethers.
Thus have I endeavoured to take one step further back into the mystery of the gravitation and repulsion of bodies, which appeared to be distant from each other, as of the sun and planets, as I before endeavoured to take one step further back into the mysteries of generation in my account of the production of the buds of vegetables in Phytologia. With what success these have been attended I now leave to the judgment of philosophical readers, from which I can make no appeal.
Fond Fancy's eye recalls the form divine,And Taste sits smiling upon Beauty's shrine.Canto III.l. 221.
The word Taste in its extensive application may express the pleasures received by any of our senses, when excited into action by the stimulus of external objects; as when odours stimulate the nostrils, or flavours the palate; or when smoothness, or softness, are perceived by the touch, or warmth by its adapted organ of sense. The word Taste is also used to signify the pleasurable trains of ideas suggested by language, as in the compositions of poetry and oratory. But the pleasures, consequent to the exertions of our sense of vision only, are designed here to be treated of, with occasional references to those of the ear, when they elucidate each other.
When any of our organs of sense are excited into their due quantity of action, a pleasurable sensation succeeds, as shown in Zoonomia, Vol. I. Sect. IV. These are simply the pleasures attending perception, and not those which are termed the pleasures of Taste; which consist of additional pleasures arising from the peculiar forms or colours of objects, or of their peculiar combinations or successions, or from other agreeable trains of ideas previously associated with them.
There are four sources of pleasure attendant on the excitation of the nerves of vision by light and colours, besides that simply of perception above mentioned; the first is derived from a degree of novelty of the forms, colours, numbers, combinations, or successions, and visible objects. The second is derived from a degree of repetition of their forms, colours, numbers, combinations, or successions. Where these two circumstances exist united in certain quantities, and compose the principal part of a landscape, it is termed picturesque bymodern writers. The third source of pleasure from the perception of the visible world may be termed the melody of colours, which will be shown to coincide with melody of sounds: this circumstance may also accompany the picturesque, and will add to the pleasure it affords. The fourth source of pleasure from the perception of visible objects is derived from the previous association of other pleasurable trains of ideas with certain forms, colours, combinations, or successions of them. Whence the beautiful, sublime, romantic, melancholic, and other emotions, which have not acquired names to express them. We may add, that all these four sources of pleasure from perceptions are equally applicable to those of sounds as of sights.
I.Novelty or infrequency of visible objects.
The first circumstance, which suggests an additional pleasure in the contemplation of visible objects, besides that of simple perception, arises from their novelty or infrequency; that is from the unusual combinations or successions of their forms or colours. From this source is derived the perpetual cheerfulness of youth, and the want of it is liable to add a gloom to the countenance of age. It is this which produces variety in landscape compared with the common course of nature, an intricacy which incites investigation, and a curiosity which leads to explore the works of nature. Those who travel into foreign regions instigated by curiosity, or who examine and unfold the intricacies of sciences at home, are led by novelty; which not only supplies ornament to beauty or to grandeur, but adds agreeable surprise to the point of the epigram, and to the double meaning of the pun, and is courted alike by poets and philosophers.
It should be here premised, that the word Novelty, as used in these pages, admits of degrees or quantities, some objects, or the ideas excited by them, possessing more or less novelty, as they are more or less unusual. Which the reader will please to attend to, as we have used the word Infrequency of objects, or of the ideas excited by them, to express the degrees or quantities of their novelty.
The source, from which is derived the pleasure of novelty, is ametaphysical inquiry of great curiosity, and will on that account excuse my here introducing it. In our waking hours whenever an idea occurs, which is incongruous to our former experience, we instantly dissever the train of imagination by the power of volition; and compare the incongruous idea with our previous knowledge of nature, and reject it. This operation of the mind has not yet acquired a specific name, though it is exerted every minute of our waking hours, unless it may be termedIntuitive Analogy. It is an act of reasoning of which we are unconscious except by its effects in preserving the congruity of our ideas; Zoonomia, Vol. I. Sect. XVII. 5. 7.
In our sleep as the power of volition is suspended, and consequently that of reason, when any incongruous ideas occur in the trains of imagination, which compose our dreams; we cannot compare them with our previous knowledge of nature and reject them; whence arises the perpetual inconsistency of our sleeping trains of ideas; and whence in our dreams we never feel the sentiment of novelty; however different the ideas, which present themselves, may be from the usual course of nature.
But in our waking hours, whenever any object occurs which does not accord with the usual course of nature, we immediately and unconsciously exert our voluntary power, and examine it by intuitive analogy, comparing it with our previous knowledge of nature. This exertion of our volition excites many other ideas, and is attended with pleasurable sensation; which constitutes the sentiment of novelty. But when the object of novelty stimulates us so forcibly as suddenly to disunite our passing trains of ideas, as if a pistol be unexpectedly discharged, the emotion of surprise is experienced; which by exciting violent irritation and violent sensation, employs for a time the whole sensorial energy, and thus dissevers the passing trains of ideas; before the power of volition has time to compare them with the usual phenomena of nature; but as the painful emotion of fear is then generally added to that of surprise, as every one experiences, who hears a noise in the dark, which he cannot immediately account for; this great degree of novelty, when it produces much surprise, generally ceases to be pleasurable, and does not then belong to objects of taste.
In its less degree surprise is generally agreeable, as it simplyexpresses the sentiment occasioned by the novelty of our ideas; as in common language we say, we are agreeably surprised at the unexpected meeting with a friend, which not only expresses the sentiment of novelty, but also the pleasure from other agreeable ideas associated with the object of it.
It must appear from hence, that different persons must be affected more or less agreeably by different degrees or quantities of novelty in the objects of taste; according to their previous knowledge of nature, or their previous habits or opportunities of attending to the fine arts. Thus before its nativity the fetus experiences the perceptions of heat and cold, of hardness and softness, of motion and rest, with those perhaps of hunger and repletion, sleeping and waking, pain and pleasure; and perhaps some other perceptions, which may at this early time of its existence have occasioned perpetual trains of ideas. On its arrival into the world the perceptions of light and sound must by their novelty at first dissever its usual trains of ideas and occasion great surprise; which after a few repetitions will cease to be disagreeable, and only excite the emotion from novelty, which has not acquired a separate name, but is in reality a less degree of surprise; and by further experience the sentiment of novelty, or any degree of surprise, will cease to be excited by the sounds or sights, which at first excited perhaps a painful quantity of surprise.
It should here be observed, that as the pleasure of novelty is produced by the exertion of our voluntary power in comparing uncommon objects with those which are more usually exhibited; this sentiment of novelty is less perceived by those who do not readily use the faculty of volition, or who have little previous knowledge of nature, as by very ignorant or very stupid people, or by brute animals; and that therefore to be affected with this circumstance of the objects of Taste requires some previous knowledge of-such kinds of objects, and some degree of mental exertion.
Hence when a greater variety of objects than usual is presented to the eye, or when some intricacy of forms, colours, or reciprocal locality more than usual accompanies them, it is termed novelty if it only excites the exertion of intuitive comparison with the usual order of nature, and affects us with pleasurable sensation; but is termedsurprise, if it suddenly dissevers our accustomed habits of motion, and is then more generally attended with disagreeable sensation. To this circumstance attending objects of taste is to be referred what is termed wild and irregular in landscapes, in contradistinction to the repetition of parts or uniformity spoken of below. We may add, that novelty of notes and tones in music, or of their combinations or successions, are equally agreeable to the ear, as the novelty of forms and colours, and of their combinations or successions are to the eye; but that the greater quantity or degree of novelty, the sentiment of which is generally termed Surprise, is more frequently excited by unusual or unexpected sounds; which are liable to alarm us with fear, as well as surprise us with novelty.
II.Repetition of visible objects.
The repeated excitement of the same or similar ideas with certain intervals of time, or distances of space between them, is attended with agreeable sensations, besides that simply of perception; and, though it appears to be diametrically opposite to the pleasure arising from the novelty of objects above treated of, enters into the compositions of all the agreeable arts.
The pleasure arising from the repetition of similar ideas with certain intervals of time or distances of space between them is a subject of great metaphysical curiosity, as well as the source of the pleasure derived from novelty, which will I hope excuse its introduction in this place.
The repetitions of motions may be at first produced either by volition, or by sensation, or by irritation, but they soon become easier to perform than any other kinds of action, because they soon become associated together; and thus their frequency of repetition, if as much sensorial power be produced during every reiteration, as is expended, adds to the facility of their production.
If a stimulus be repeated at uniform intervals of time, the action, whether of our muscles or organs of sense, is produced with still greater facility or energy; because the sensorial power of association,mentioned above, is combined with the sensorial power of irritation; that is in common language, the acquired habit assists the power of the stimulus.
This not only obtains in the annual, lunar, and diurnal catenations of animal motions, as explained in Zoonomia, Sect. XXXVI. which are thus performed with great facility and energy; but in every less circle of actions or ideas, as in the burden of a song, or the reiterations of a dance. To the facility and distinctness, with which we hear sounds at repeated intervals, we owe the pleasure, which we receive from musical time, and from poetic time, as described in Botanic Garden, V. II. Interlude III. And to this the pleasure we receive from the rhimes and alliterations of modern versification; the source of which without this key would be difficult to discover.
There is no variety of notes referable to the gamut in the beating of a drum, yet if it be performed in musical time, it is agreeable to our ears; and therefore this pleasurable sensation must be owing to the repetition of the divisions of the sounds at certain intervals of time, or musical bars. Whether these times or bars are distinguished by a pause, or by an emphasis, or accent, certain it is, that this distinction is perpetually repeated; otherwise the ear could not determine instantly, whether the successions of sound were in common or in triple time.
But besides these little circles of musical time, there are the greater returning periods, and the still more distinct choruses; which, like the rhimes at the end of verses, owe their beauty to repetition; that is, to the facility and distinctness with which we perceive sounds, which we expect to perceive or have perceived before; or in the language of this work, to the greater ease and energy with which our organ is excited by the combined sensorial powers of association and irritation, than by the latter singly.
This kind of pleasure arising from repetition, that is from the facility and distinctness with which we perceive and understand repeated sensations, enters into all the agreeable arts; and when it is carried to excess is termed formality. The art of dancing like that of music depends for a great part of the pleasure, it affords, on repetition; architecture, especially the Grecian, consists of one part being a repetitionof another, and hence the beauty of the pyramidal outline in landscape-painting; where one side of the picture may be said in some measure to balance the other. So universally does repetition contribute to our pleasure in the fine arts, that beauty itself has been defined by some writers to consist in a due combination of uniformity and variety: Zoonomia, Vol. I. Sect. XXII. 2. 1.
Where these repetitions of form, and reiterations of colour, are produced in a picture or a natural landscape, in an agreeable quantity, it is termed simplicity, or unity of character; where the repetition principally is seen in the disposition or locality of the divisions, it is called symmetry, proportion, or grouping the separate parts; where this repetition is most conspicuous in the forms of visible objects, it is called regularity or uniformity; and where it affects the colouring principally, the artists call it breadth of colour.
There is nevertheless, an excess of the repetition of the same or similar ideas, which ceases to please, and must therefore be excluded from compositions of Taste in painted landscapes, or in ornamented gardens; which is then called formality, monotony, or insipidity. Why the excitation of ideas should give additional pleasure by the facility and distinctness of their production for a certain time, and then cease to give additional pleasure; and gradually to give less pleasure than that, which attends simple exertion of them; is another curious metaphysical problem, and deserves investigation.
In our waking hours a perpetual voluntary exertion, of which we are unconscious, attends all our new trains of ideas, whether those of imagination or of perception; which by comparing them with our former experience preserves the consistency of the former, by rejecting such as are incongruous; and adds to the credibility of the latter, by their analogy to objects of our previous knowledge: and this exertion is attended with pleasurable sensation. After very frequent repetition these trains of ideas do not excite the exertion of this intuitive analogy, and in consequence are not attended with additional pleasure to that simply of perception; and by continued repetition they at length lose even the pleasure simply of perception, and thence finally cease to be excited; whence one cause of the torpor of old age, and of death, as spoken of in Additional Note, No. VII. 3. of this work.
When there exists in any landscape a certain number and diversity of forms and colours, or of their combinations or successions, so as to produce a degree of novelty; and that with a certain repetition, or arrangement of parts, so as to render them gradually comprehensible or easily compared with the usual course of nature; if this agreeable combination of visible objects be on a moderate scale, in respect to magnitude, and form the principal part of the landscape, it is termedPicturesqueby modern artists; and when such a combination of forms and colours contains many easy flowing curves and smooth surfaces, the delightful sentiment ofBeautybecomes added to the pleasure of the Picturesque.
If the above agreeable combination of novelty and repetition exists on a larger scale with more projecting rocks, and deeper dells, and perhaps with a somewhat greater proportion of novelty than repetition, the landscape assumes the name ofRomantic; and if some of these forms or combinations are much above the usual magnitude of similar objects, the more interesting sentiment ofSublimitybecomes mixed with the pleasure of the romantic.
III.Melody of Colours.
A third source of pleasure arising from the inspection of visible objects, besides that of simple perception, arises from what may be termed melody of colours, as certain colours are more agreeable, when they succeed each other; or when they are disposed in each other's vicinity, so as successively to affect the organ of vision.
In a paper on the colours seen in the eye after looking for some time on luminous objects, published by Dr. Darwin of Shrewsbury in the Philos. Trans. Vol. 76, it is evidently shown, that we see certain colours not only with greater ease and distinctness, but with relief and pleasure, after having for some time inspected other certain colours; as green after red, or red after green; orange after blue, or blue after orange; yellow after violet, or violet after yellow; this, he shows, arises from the ocular spectrum of the colour last viewed coinciding with the irritation of the colour now under contemplation.
Thus if you make a dot with ink in the centre of a circle of red silk the size of a letter-wafer, and place it on a sheet of white paper, and look on it for a minute without moving your eyes; and then gently turn them on the white paper in its vicinity, or gently close them, and hold one hand an inch or two before them, to prevent too much light from passing through the eyelids, a circular spot of pale green will be seen on the white paper, or in the closed eye; which is called the ocular spectrum of the red silk, and is formed as Dr. Darwin shows by the pandiculation or stretching of the fine fibrils, which constitute the extremities of the optic nerve, in a direction contrary to that, in which they have been excited by previously looking at a luminous object, till they become fatigued; like the yawning or stretching of the larger muscles after acting long in one direction.
If at this time the eye, fatigued by looking long at the centre of the red silk, be turned on paper previously coloured with pale green; the circular spot or ocular spectrum will appear of a much darker green; as now the irritation from the pale green paper coincides with the pale green spectrum remaining in the eye, and thus excites those fibres of the retina into stronger action; on this account some colours are seen more distinctly, and consequently more agreeably after others; or when placed in the vicinity of others; thus if orange-coloured letters are painted on a blue ground, they may be read at as great distance as black on white, perhaps at a greater.
The colours, which are thus more distinct when seen in succession are called opposite colours by Sir Isaac Newton in his optics, Book I. Part 2, and may be easily discovered by any one, by the method above described; that is by laying a coloured circle of paper or silk on a sheet of white paper, and inspecting it some time with steady eyes, and then either gently closing them, or removing them on another part of the white paper, and the ocular spectrum or opposite colour becomes visible in the eye.
Sir Isaac Newton has observed, that the breadths of the seven primary colours in the sun's image refracted by a prism, are proportioned to the seven musical notes of the gamut; or to the intervals of the eight sounds contained in an octave.
From this curious coincidence, it has been proposed to produce aluminous music, consisting of successions or combinations of colours, analogous to a tune in respect to the proportions above mentioned. This might be performed by a strong light, made by means of Mr. Argand's lamps, passing through coloured glasses, and falling on a defined part of the wall, with moveable blinds before them, which might communicate with the keys of a harpsichord, and thus produce at the same time visible and audible music in unison with each other.
Now as the pleasure we receive from the sensation of melodious notes, independent of musical time, and of the previous associations of agreeable ideas with them, must arise from our hearing some proportions of sounds after others more easily, distinctly, or agreeably; and as there is a coincidence between the proportions of the primary colours, and the primary sounds, if they may be so called; the same laws must probably govern the sensations of both. In this circumstance therefore consists the sisterhood of Music and Painting; and hence they claim a right to borrow metaphors from each other: musicians to speak of the brilliancy of sounds, and the light and shade of a concerto; and painters of the harmony of colours, and the tone of a picture.
This source of pleasure received from the melodious succession of colours or of sounds must not be confounded with the pleasure received from the repetition of them explained above, though the repetition, or division of musical notes into bars, so as to produce common or triple time, contributes much to the pleasure of music; but in viewing a fixed landscape nothing like musical time exists; and the pleasure received therefore from certain successions of colours must depend only on the more easy or distinct action of the retina in perceiving some colours after others, or in their vicinity, like the facility or even pleasure with which we act with contrary muscles in yawning or stretching after having been fatigued with a long previous exertion in the contrary direction.
Hence where colours are required to be distinct, those which are opposite to each other, should be brought into succession or vicinity; as red and green, orange and blue, yellow and violet; but where colours are required to intermix imperceptibly, or slide into each other, these should not be chosen; as they might by contrast appeartoo glaring or tawdry. These gradations and contrasts of colours have been practically employed both by the painters of landscape, and by the planters of ornamental gardens; though the theory of this part of the pleasure derived from visible objects was not explained before the publication of the paper on ocular spectra above mentioned; which is reprinted at the end of the first part of Zoonomia, and has thrown great light on the actions of the nerves of sense in consequence of the stimulus of external bodies.
IV.Association of agreeable sentiments with visible objects.
Besides the pleasure experienced simply by the perception of visible objects, it has been already shown, that there is an additional pleasure arising from the inspection of those, which possess novelty, or some degree of it; a second additional pleasure from those, which possess in some degree a repetition of their parts; and a third from those, which possess a succession of particular colours, which either contrast or slide into each other, and which we have termed melody of colours.
We now step forward to the fourth source of the pleasures arising from the contemplation of visible objects besides that simply of perception, which consists in our previous association of some agreeable sentiment with certain forms or combinations of them. These four kinds of pleasure singly or in combination constitute what is generally understood by the word Taste in respect to the visible world; and by parity of reasoning it is probable, that the pleasurable ideas received by the other senses, or which are associated with language, may be traced to similar sources.
It has been shown by Bishop Berkeley in his ingenious essay on vision, that the eye only acquaints us with the perception of light and colours; and that our idea of the solidity of the bodies, which reflect them, is learnt by the organ of touch: he therefore calls our vision the language of touch, observing that certain gradations of the shades of colour, by our previous experience of having examined similar bodies by our hands or lips, suggest our ideas of solidity, andof the forms of solid bodies; as when we view a tree, it would otherwise appear to us a flat green surface, but by association of ideas we know it to be a cylindrical stem with round branches. This association of the ideas acquired by the sense of touch with those of vision, we do not allude to in the following observations, but to the agreeable trains or tribes of ideas and sentiments connected with certain kinds of visible objects.
V.Sentiment of Beauty.
Of these catenations of sentiments with visible objects, the first is the sentiment of Beauty or Loveliness; which is suggested by easy-flowing curvatures of surface, with smoothness; as is so well illustrated in Mr. Burke's Essay on the Sublime and Beautiful, and in Mr. Hogarth's analysis of Beauty; a new edition of which is much wanted separate from his other works.
The sentiment of Beauty appears to be attached from our cradles to the easy curvatures of lines, and smooth surfaces of visible objects, and to have been derived from the form of the female bosom; as spoken of in Zoonomia, Vol. I. Section XVI. on Instinct.
Sentimental love, as distinguished from the animal passion of that name, with which it is frequently accompanied, consists in the desire or sensation of beholding, embracing, and saluting, a beautiful object.
The characteristic of beauty therefore is that it is the object of love; and though many other objects are in common language called beautiful, yet they are only called so metaphorically, and ought to be termed agreeable. A Grecian temple may give us the pleasurable idea of sublimity; a Gothic temple may give us the pleasurable idea of variety; and a modern house the pleasurable idea of utility; music and poetry may inspire our love by association of ideas; but none of these, except metaphorically, can be termed beautiful; as we have no wish to embrace or salute them.
Our perception of beauty consists in our recognition by the sense of vision of those objects, first which have before inspired our love bythe pleasure, which they have afforded to many of our senses: as to our sense of warmth, of touch, of smell, of taste, hunger and thirst; and secondly, which bear any analogy of form to such objects.
When the babe, soon after it is born into this cold world, is applied to its mother's bosom, its sense of perceiving warmth is first agreeably affected; next its sense of smell is delighted with the odour of her milk; then its taste is gratified by the flavour of it, afterwards the appetites of hunger and of thirst afford pleasure by the possession of their objects, and by the subsequent digestion of the aliment; and lastly, the sense of touch is delighted by the softness and smoothness of the milky fountain, the source of such variety of happiness.