musical birds, and been conducted, by a band of songsters, to the habitation of his fellow-creatures. On the other hand, the silent birds, and such as have harsh and disagreeable voices, generally inhabit the inaccessible wilds, the gloomy forest, or the distant parts of the ocean. There their screaming notes overcome the noise of the winds and water, and prevent them from being dispersed from each other amidst the fury of these tempestuous elements. Further, it is not often, that those birds which are capable of imitating sounds are possessed of what may be called a taste for music. They have no predilection for melodious notes; but will imitate the harshest screams as readily as the finest air. They seem, in a great degree, in sensible to the effect of their own powers, and the charms which they possess; for it does not appear that the birds of one species are delighted with the warblings of those of a different. Man, however, derives pleasure from them all; a pleasure which never rises higher than when it is produced by the combined effect of every note in the grove. MOTA'TION. s. Act of moving. MOTE. s. (mor, Saxon.) A small particle of matter; any thing proverbially little (Bacon). MOTE, for might, or must (Spenser). MOTE, MOTA. (Fr. mot, a word.) Discussion, debate. It is a word which frequently occurs, in our ancient customs, for a meeting, court, or plea. The term is still retained in Iaw under the form of Moor. Of motes, by the Saxons also called gemotes, considered in the sense of assemblies, or courts, there were divers kinds; as wittenagemote, folkegemote, schiregemote, hundredgemote, burgemote, wardegemote, haligemote, swaine gemote, &c. See each under its proper article, WITIENAGEMOTE, FOLKEGEMOTE, &c. MOTE, mota, was also used for a fortress, or castle; as, mota de Windsor, &c. MOTE also denoted a standing water to keep fish in; and sometimes a large ditch encompassing a castle, or dwelling-house. MOTETTO, in the Italian music, a kind of church-music, composed with much art and ingenuity from one to eight parts, with or without instruments, usually accompanied with a thorough bass. When the composer gives a loose to his fancy, without confining himself to any rules, subjects or passions, it is called fantasia or ricercata. The word is sometimes used for pieces made to hymns to saints, &c. and whole psalms are often thus called; and was probably derived from motus, motion, because the church songs were designed to move the hearts of the hearers; or because this kind of composition was originally of a very gay and lively nature. MOTH, in entomology. See PHALENA. MOTHER. 8. (modon, Saxon.) 1. A woman that has borne a child; correlative to son or daughter (Shakspeare). 2. That which has produced any thing (Arb.). 3. That which has preceded in time: as, a mother church to chapels. 4. That which requires reverence and obedience (Ayliffe). 5. Hysterical passion (Graunt). 6. A familiar term of address to an old woman. 7. (moeder, Dutch.) A thick substance concreting in liquors; the lees or scum concreted (Dryden). MOTHER-IN-LAW. S. The mother of a husband or wife (Matthew). white and irridescent enamel that lines the inMOTHER OF PEARL. The beautiful terior of the shell of the mytilus margaritiferus, or mother of pearl mussel, (see MYTILUS): the shell being thus denominated from its generating this elegant lining. This shell grows to a very considerable size, is of a flattened and rounded shape, with the back or hingepart straight. From this cartilaginous hinge, when in a petrified state, is very rare and beanful extraneous fossil called the astrodamas (helmintholithus astrodamas of Linneus); which when cut and polished, in the disposition of its fibres, and in its colours, bears some resemblance to the eye of a peacock's feather. Mother of pearl is also sometimes obtained from the shells of some species of the mya, and of the oyster, but by far the best specimens are obtained from the mother of pearl inussel-shell. It is occasionally found, however, in the haliotis iris, and turbo olearius, but the membranaceous parts of these shells are more compact and dense than those of the mytilus margaritiferus. These shells, when deprived of their hardening substance, or carbonat of lime, by an acid menstruum, appear to be formed of various membranes applied stratum super stratum. Each membrane has a corresponding coat, or crust of carbonat of lime, which is so situate that it is always between every two membranes, beginning with the epidermis, and ending with the last formed internal membrane. The animals which inhabit these stratified shells increase their habitation by the addition of a stratum of carbonat of lime, secured by a new membrane; and as every additional stratum exceeds in extent that which was previously formed, the shell becomes stronger in proportion as it is enlarged, and the growth and age of the animal is denoted by the number of the stratum which concur in forming the shell. For the chemical properties of mother of pearl, see the article CONCHOLOGY. MOTHER OF THYME. See THYMUS. MOTHERHOOD. s. (from mother.) The office or character of a mother (Donne). MOTHERLESS. a. (from mother.) Destitute of a mother (Waller). MOTHERLY. a. (mother and like.) Belonging to a mother; suitable to a mother (Ral.). MOTHERLY. ad. (from mother.) In manner of a mother (Donne). MOTHERY.a. (from mother.) Concreted; full of concretions; dreggy; feculent. MOTHMU'LLEIN. s. (blatteria, Latin.) A plant (Miller). MOTHY. a. (from moth.) Full of moths. MOTION. s. (motio, Latin.) 1. The act of changing place (Milton). 2. Manner of moving the body; port; gait (Waller). Change of posture; action (Dryden). 4. Agitation; intestine action (Gay). 5. Direction; 3. tendency (Millon). 6. Impulse communi- MOTION, primarily so called, or local motion, has been defined a continued and successive change of place; or that state of a body, whereby it corresponds successively to several different places, or is present successively in different parts of space. In this sense, the doctrine and laws of motion make the subject of mechanics, or dynamics. The ancient philosophers considered motion in a more general and extensive manner; they defined it a passage out of one state into another; and thus made six kinds of motion, viz. creation, generation, corruption, augmentation, diminution, and lation, or local motion. Some of the later schoolmen reduce these six kinds of motion to four: the first is general, including any passage from one state to another; under which kind come creation, production, and mutation. The second is a passage of something already existing from one state to another; and thus generation is a motion. The third is a successive passage of something already existing from one term to another; and thus alteration, and accretion, are species of motion. The last is lation, or local motion; and thus walking is motion. But the latest philosophers deny any other species besides local motion; and reduce all the sorts above-mentioned to this one. So that we bave here only to do with lation, or local motion; whereof the rest are only so many different determinations, or effects. Physical writers, both ancient and modern, have ever been perplexed about the nature and definition of local motion. The Peripatetics define it by, Actus entis in potentia, prout in potentia, Arist. 3. Phys. cap. 2. but this notion seems too abstract and metaphysical for our days, and is of no use in explaining the properties of motion. The Epicureans explain motion by the migration of a body, or a part of a body from one place to another; on which definition the later Epicureans refine, and call it, the migration or passage of a body from space to space; thus substituting the word space for that of place. . The Cartesians define motion, a passage or removal of one part of matter out of the neighbour hood of those parts immediately contiguous thereto, into the neighbourhood of others. Which definition, agrees, in effect, with that of the Epicureans: all the difference between them consisting in this; that what the one call body, and place, the other call matter, and contiguous parts. Borelli, and other late writers after him, define motion more accurately and fully, the successive passage of a body from one place to another, in a determinate time, by becoming successively con. tiguous to all the parts of the intermediate space. Motion, then, is agreed to be the translation of a body from place to place; but authors differ much when they come to explain wherein this translation consists. And hence their divisions of motion become exceedingly precarious. Aristotle, and the Peripatetics, divide all motion into natural and violent. MOTION (Natural), is that which has its principle, or moving force, within the moving body. Such is that of a stone falling towards the centre of the earth. MOTION (Violent), is that whose principle is The moderns generally divide motion into " solute and relative. MOTION (Absolute), is the change of abute place, in any moving body; whose celerity Dere fore, will be measured by the quantity of solute thrigh. space which the moveable body runs MOTION (Relative), is a mutation, the rela tive or vulgar place of the moving bo and has its celerity estimated by the quanti space run through. A late acute writer, Mr. Young of relative efines motion, change of place; and as he ende ours to obviate This is the ablest defence of an attempt to define motion that we have ever seen; and at first view the definition itself appears to be perfect. Aristotle, the prince of definers," considers a definition as a speech declaring what a thing is. Every thing essential to the thing defined, and nothing more, must be contained in the definition. Now the essence of a thing consists of these two parts; first, what is common to it with other things of the same kind; and secondly, what distinguishes it from other things of the same kind. The first is called the genus of the thing; the second, its specific difference. The definition, therefore, consists of those two parts." In obedience to this rule, the definition under consideration seems to consist of the genus, signi fied by the word change; and of the specific difference, denoted by the words of place. But does the speech change of place really declare what motion is? We cannot admit that it does; as, in our apprehension, a change of place is the effect of motion, and not motion itself. Suppose a lover of dialectics undertaking to define the stroke by which he saw his neighbour wounded with a bludgeon; what should we think of his art were he to call it a contusion on the head? He might say that contusion is a general term, as contusions may be produced on the arms, on the legs, and on various parts of the body; and as there are many species of contusion, if he were asked which of those species was the stroke to be defined, be might answer, a contusion on the head.".. Here would be apparently the genus and specific difference; the former denoted by contusion, and the latter by the words on the head, But ould this be a definition of a stroke? No, surely: contusion on the head may be the effect of a ste; but it can no more be the stroke itself, tha blow can be a bludgeon, or a flesh wound the poin,f a sword. Equally evident it is, that a chang of place cannot be motion; because every body not have been actually moved before we can disc, or even conceive, a change of its place. The act changing place would perhaps come nearer to a finition of motion; but so far would it be from "peech declaring what motion is," that we are cordent a man who had never by any of his senses peeived a body in actual motion, would acquire nideas whatever from the words, "act of changing Pe." He might have experienced changes in heat, cd, smell, and sound; but he could not possibly mbine the ideas of changes with the significationof the word place, were he even capable of andstanding that word, which to us appears to be mo, than doubtful. The distinctions of tion into different kinds have been no less variou, and no less insignificant, than the several denitions of it. The moderns who reject the pebatetic division of motion into four classes, yet onsider it themselves as either absolute or relativ Thus we are told, as above, that "absolute motin is the change of absolute place, and that its celery must be measured by the quantity of absolut space which the moving body runs through in a iven time." "Relative motion, on the other han, is a mutation of the relative or vulgar place of the moving body, and has its celerity estimated by the quantity of relative space run through." Now it is obvious, that this distnction conveys no ideas without a farther explanation of the terms by which it is expressed; butthat explananation is impossible to be given. Thus, before we can understand what absolute motion is, we must understand what is meant by absolute place. But absolute place is a contradiction; for all place is relative, and consists in the positions of different bodies with regard to one another. Were a globe in the regions of empty space to be put in motion by Almighty Power, and all the rest of the corporeal world to be soon afterwards annihilated, the motion would undoubtedly continue unchanged; and yet according to this distinction, it would be at first relative, and afterwards absolute. That the beginning of such a motion would be perceptible, and the remainder of it imperceptible, is readily granted; but on this account to consider it as of two kinds, is as absurd as to suppose the motion of the minute-hand of a clock to be affected by our looking at it. But we dare not dwell longer upon these distinctions. MOTION (Laws of). See AXIOMS and DYNA MICS. MOTION (Quantity of), whether always the same? The Cartesians maintained that the Creator at the beginning impressed a certain quantity of motion on bodies; and that under such laws, as that no part of it should be lost, but the same portion of motion should be constantly preserved in matter: and hence they conclude, that if any moving body strike on any other body, the former loses no more of its motion than it communicates to the latter. This principle sir Isaac Newton overturns in the following words: "From the various compositions of two motions, it is manifest there is not always the same quantity of motion in the world; for if two balls, joined together by Some philosophers, after Descartes, have supposed the preservation of the same force or vis viva. See the articles FORCE and Vis viva. But this holds only in elastic bodies, when there is a shock; and hence those philosophers have been led to maintain, that all bodies were elastic, at least in their elements, and that an inflexible body was impossible, being repugnant to the law of continuity. See DYNAMICS. MOTION (Equable), is that by which the moving body proceeds with exactly the same velocity or celerity; passing always over equal spaces in equal times. The laws of uniform Motion are these: 1. The spaces described, or passed over, are in the compound ratio of the velocities, and the times of describing those spaces. So that, if V and v be any two uniform velocities, S and s the spaces described or passed over by them, in the respective times T and t: then is Ss :: TV: to, or 20: 12:4x5:3×4; taking T=4, t=3, V=5, and v=4. 9. In uniform motions, the time is as the space directly, and as the velocity reciprocally; or as the space divided by the velocity. So that MOTION (Accelerated), is that which continually receives fresh accessions of velocity. And it is said to be uniformly accelerated, when its accessions of velocity are equal in equal times; such as that which is produced by the continual action of one and the same force, like the force of gravity, &c. MOTION (Retarded), is that whose velocity continually decreases. And it is said to be uniformly retarded, when its decrease is continually proportional to the time, or by equal quantities in equal times; like that which is produced by the continual opposition of one and the same force; such is the force of gravity in uniformly retarding the motion of a body that is thrown upwards. The laws of motion, uniformly accelerated or retarded, are these: 1. In uniformly varied motions, the space, S or , is as the square of the time, or as the square of the greatest velocity, or as the rectangle or product of the time and velocity. That is, S: s:: T2 : 12 : : V2 : v2 : ; TV : tu. 2. The velocity is as the time, or as the space divided by the time, or as the square root of the space. S T t 3. The time is as the velocity, or as the space divided by the velocity, or as the square root of the space. That is, TV: 0 :: S ບ S :- :: NS: √s. V 4. When a space is described, or passed over, by an uniformly varied motion, the velocity either beginning at nothing, and continually accelerated; or else beginning at some determinate velocity, and continually retarded till the velocity be reduced to nothing; then the space, so run over by the variable motion, will be exactly equal to half the space that would be run over in the same time by the greatest velocity if uniformly continued for that time. See ACCELERATION. MOTION (Perpetual), is a motion which is supplied and renewed from itself, without the intervention of any external cause. The celebrated problem of a perpetual motion consists in the inventing a machine, which has the principle of its motion within itself; and is a problem that has employed the mathematicians for 2000 years; though none perhaps have prosecuted it with attention and earnestness equal to those of the present age. Infinite are the schemes, designs, plans, engines, wheels, &c. to which this long-desired perpetual motion has given birth. But M. De la Hire has proved the impossibility of any such machine, and finds that it amounts to this; viz. to find a body which is both heavier and lighter at the same time; or to find a body which is heavier than itself. Indeed there seems but little in nature to countenance all this assiduity and expectation: among all the laws of matter and motion, we know of none yet that seem likely to furnish any principle or foundation for such an effect. Action and re-action it is allowed are always equal; and a body that gives any quantity of motion to another, always loses just so much of its own; but under the present state of things, the resistance of the air, the friction of the parts of machines, &c. do necessarily retard every motion. To continue the motion therefore either, first, there must be a supply from some foreign cause; which in a perpetual motion is excluded. Or, 2dly, all resistance from the friction of the parts of matter must be removed; which neces sarily implies a change in the nature of things. Or, 3dly and lastly, there must be some method of gaining a force equivalent to what is lost, by the artful disposition and combination of mechanic powers; to which last point then all endeavours are to be directed: but how, or by what means, such force should be gained, is still a mystery. The multiplication of powers or forces, it is certain, avails nothing; for what is gained in power is lost in time, so that the quantity of motion still remains the same. This is an inviolable law of nature; by which nothing is left to art, but the choice of the several combinations that may produce the same effect. MOTION, in astronomy, is peculiarly applied to the orderly courses of the heavenly bodies. The motions of the celestial luminaries are of two kinds: diurnal, or common; and secondary, or proper. MOTION (Diurnal, or primary), is that with which all the heavenly bodies, and the whole mundane sphere, appear to revolve every day round the earth, from east to west. This is also called the motion of the primum mobile, and the common motion, to distinguish it from that rotation which is peculiar to each planet, &c. MOTION (Secondary, or proper), is that with which a star, planet, or the like, advances a certain space every day from the west towards the east. See the several motions of each luminary, with the irregularities, &c. of them under the proper articles, EARTH, MOON, STAR, &c. MOTION (Angular), is that by which the angular position of any thing varies. See ANGULAR. MOTION (Horary), is the motion during each hour. See HORARY. MOTION (Paracentric) of Impetus. See PARA CENTRIC. MOTION of Trepidation, &c. See TREPIDATION and LIBRATION. MOTION (Muscular.) See MUSCLES. MOTION (Peristaltic.) See PERISTALTIC. MOTION, in the manage. A horse is said to have a good motion when he moves and bends his forelegs with great ease and freedom upon the manage. But if a horse trot right out, and keeps his body straight and his head high, and bends his fore-legs handsomely, then to say he has a good moxien im plies the liberty of the action of the fore-hand. See the articles ACTION, PROGRESSION, &C. MOTIONLESS. a. (from motion.) Wanting motion; being without motion (Black.). MOTIVE. a. (motivus, Lat.) 1. Causing motion; having motion (Hooker). 2. Having the power to move; having power to change place (Wilkins). MOTIVE POWER OF FORCE, is the whole power or force acting upon any body, or quantity of matter, to move it; and is proportional to the momentum or quantity of motion it can produce in a given time. To distinguish it from the accelerative force, which is considered as affecting the celerity only. MOTIVE. s. (motif, French.) 1. That which determines the choice; that which incites the action (Locke). 2. Mover. not in use (Shakspeare). MOTLEY. a. Mingled of various colours. TUS. MOTO. (Ital.) In music, a word applied adverbially to the manner or style of performing any composition; and signifying that it is to be sung or played with emphasis and agi tation. MOTO CONTRARIO. (Ital.) An expression applied to that progression of the different harmonic parts of a composition by which they move in opposite directions. MOTORII OCULORUM. (nervi motori, so called from their office.) The third pair of nerves of the brain. They arise from the crura cerebri, and are distributed on the muscles of the bulb of the eye. MOTORY. a. (motorius, Latin.) Giving motion (Ray). MOTOUÁLIS, a small nation of Syria, inhabiting to the east of the country of the Drusas, in the valley which separates their mountains from those of Damascus. MOTTE (Anthony Houdart de la), an ingenious Frenchman, greatly distinguished by his writings in prose and verse, and by his literary contests with many eminent persons, was born at Paris in 1672. He wrote with very different success, no man having been more praised or more criticised than he was: his literary paradoxes, his singular systems in all branches of polite learning, and above all his judgment upon the ancients, which, like those of Perrault, were thought disrespectful and detracting, raised him up formidable adversaries. Racine, Boilean, Rousseau, and madam Dacier, were among the number of those who made it their business to avenge antiquity on a man who, with more wit than genius or learning, assumed a kind of dictatorial authority in the province of belles lettres. He became blind in the latter years of his life, and died in 1731. He wrote a great deal in epic poetry, tragedy, comedy, lyric, pastoral, and fables; besides a vast variety of discourses, critical and academical, in prose. A complete edition of all his works was published in 11 vols. 8vo, in 1754; though, as has been said of our Swift, 靠 his reputation had been better consulted by re- : ducing them to three or four. MOTTO. s. (motto, Italian.) A sentence or word added to a device, or prefixed to any thing written (Addison). To MOVE. v. a. (moveo, Latin.) 1. To put out of one place into another; to put in motion (Job). 2. To give an impulse to (Decay of Piety). 3. To propose; to recommend (Davies). 4. To persuade; to prevail on (South). 5. To affect; to touch pathetically; to stir passion (Dryden). 6. To make angry (Shakspeare). 7. To put into commotion (Ruth). 8. To incite (Milton). 9. To conduct regularly in motion (Milton). To Move. v. n. 1. To be in a state of changing place (Milton). 2. To go from one place to another (Shakspeare). 3. To walk; to bear the body (Dryden). 4. To go forward (Dryden). 5. To change the posture of the body in ceremony (Esther). MOVEABLE. a. (from move.) 1. Capable of being moved; not fixed; portable (Addis.). 2. Changing the time of the year (Holder). MOVEABLE FEASTS, are such as are not always held on the same day of the year or month; though they may be on the same day of the week. Thus, Easter is a moveable feast; being always held on the Sunday which falls upon or next after the first full moon following the 21st of March. See Philos. Trans. Numb. 240, p. 185. All the other moveable feasts follow Easter, keeping their constant distance from it; so that they are fixed with respect to it, though moveable through the course of the year. Such are Septuagesima, Sexagesima, Ash-Wednesday, Ascension-day, Pentecost, Trinity-Sunday, &c. MOVEABLES. s. (meubles, Fr.) Goods; furniture: distinguished from real or immoveable possessions, as lands or houses (Shak.). MOVEABLENESS. s. (from moveable.) Mobility; ; possibility to be moved. MOVEABLY. ad. (from moveable.) So as it may be moved (Grew). MÓVELESS. a. Unmoved; not to be put out of the place (Boyle). MOVEMENT. s. (mouvement, French.) 1. Manner of moving (Pope). 2. Motion (Pope). MOVEMENT, a term often used in the same sense with automaton. The most usual movements for keeping time, are clocks and watches: the latter are such as shew the parts of time by inspection, and are portable in the pocket; the former such as publish it by sounds, and are fixed as furniture. MOVEMENT, in music, the name given to any single strain, or to any part of a composition comprehended under the same measure, or time. When an overture, concerto, song, or any other piece, changes its time and measure, either from one species to another, as from commen-time to triple, or vice versa ; or in the same species, as from triple-time, adagio, to triple-time, allegro, or the contrary; it is then said to change its movement: so that every composition consists of as many move |