of Composite Semiflosculosa. Cichoraceæ, Jussieu. Essential character: calyx imbricate, ventricose; down hairy; receptacle naked. There are nineteen species.

SONG, in poetry, a little composition, consisting of easy and natural verses, set to a tune in order to be sung.

SONG of birds. The song of birds has been defined to be a succession of three or four different notes, which are continued without interruption through the same intervals, in a bar of four crotchets, adagio, or while a pendulum swings four seconds. It is observed, that notes in birds are no more innate than language in man, and that they depend entirely on the master under which they are bred, as far as their organs will enable them to imitate the sounds which they have frequent opportunities of hearing; and their adhering so steadily, even in a wild state, to the same song, is entirely owing to the nestlings attending only to the instruction of the parent-bird, whilst they disregard the notes of all others that may perhaps be singing round them. Birds, in a wild state, do not commonly sing more than six or seven months out of the twelve; but birds that are caged, and have plenty of food, sing the greatest part of the year; and we may add, that the female of no species of birds ever sings. It has been remarked, that there is no instance of any bird singing, whose size exceeds that of our black-bird; and this is supposed to arise from the difficulty it would have of concealing itself, did it call the attention of its enemies, not only by its bulk, but by the proportionable loudness of its notes. It has been noticed by some writers, that certain passages of the song in a few kinds of birds correspond with the intervals of our scale, of which indeed the cuckoo affords a striking and well known instance; but much the greater part of such song is not capable of musical notation; partly because the rapidity is often so great, and it is also so uncertain when they may stop, that we cannot reduce the passages to the form of any musical bar whatsoever; partly also because the pitch of most birds is considerably higher than that of the shrillest notes of our highest instruments; and principally because the intervals used by birds are commonly so minute, and consequently so different from the more gross intervals into which we divide our octave, that we cannot judge of them. Most people, who have not attended to the notes of birds,

suppose that all those of the same species sing exactly the same notes and passages, which is by no means true, though it must be admitted that there is a general resemblance. Thus the London birdcatchers prefer the song of the Kentish goldfinches, and Essex chaffinches; but some of the nightingale-fanciers prefer a Surry bird to one of Middlesex. The nightingale has been almost universally esteemed the most capital of singing birds; and its superiority chiefly consists in the following particulars: its tone is much more mellow than that of any other bird, though, by the exertion of its powers, it can be extremely brilliant. Another point of superiority is its continuance of song without a pause, which is often extended to twenty seconds.

SONG, in music, is applied in general to a single piece of music, whether contrived for the voice or an instrument. A song has been compared to an oration; for as, in this latter, there is a subject, viz. some person or thing the discourse is referred to, and which is always to be kept in view through the whole; so, in every regular and melodious song, there is one note which regulates the rest; wherein the song begins, and at last ends: and which is, as it were, the principal matter, or musical subject, to be regarded in the whole course of the song; and this principal or fundamental note is called the key of the song.

SONNERATIA, in botany, so named in memory of Mons. Sonnerat, a genus of the Icosandria Monogynia class and order. Natural order of Hesperidex. Myrti, Jussieu. Essential character: calyx six-cleft; petals six, lanceolate; berry many-celled, with several seeds in each cell. There is but one species, viz. S. acida, a native of the Molucca islands and the bogs of New Guinea; also of Cochin China, on the banks of rivers.

SOOT, a volatile matter, arising from wood, and other fuel, along with the smoke; or rather, it is the smoke itself, fixed and gathered on the sides of the chimney.

SOPHISM, in logic, &c. an argument which carries much of the appearance of truth, and yet leads into error. There is some need of a particular description of these fallacious arguments, that we may with more ease and readiness detect and solve them. 1. The first sort of sophism is called "ignoratio elenchi;" or a mistake of the question. 2. The next sophism is called "petitio principii," or a supposition of what is not granted. 3. That sort of

fallacy, which is called a circle, is very near a-kin to the "petitio principii." 4.The next sort af sophism is called "non causa pro causa," or the assignation of a false cause. 5. The next is called "fallacia accidentis," or a sophism, wherein we pronounce concerning the nature and essential properties of any subject, according to something which is merely accidental to it. 6. The next sophism borders upon the former; and that is, when we argue from that which is true, absolutely, simply, and abstracted from all circumstances; this is called, in the schools, a sophism "a dicto secundum quid ad dictum simpliciter." This sort of sophism has also its reverse; as, when we argue from that which is true, simply and absolutely, to prove the same thing true in all particular circumstances whatsoever. 7. The sophisms of composition and division come next to be mentioned. The sophism of composition is, when we infer any thing concerning ideas in a compound sense, which is only true in a divided sense. The sophism of division is, when we infer the same thing concerning ideas in a divided sense, which is only true in a compounded one. This sort of sophism is committed, when the word all is taken in a collective and distributive sense, without a duc distinction. It is the same fallacy, when the universal word all, or no, refers to species in one proposition, and to the individuals in another. 8. The last sort of sophisms arises from our abuse of the ambiguity of words, which is the largest and most extensive kind of fallacy; and, indeed, several of the former fallacies might be reduced to this head. When the words or phrases are plainly equivocal, they are called sophisms of equivocation. This sophism, as well as the foregoing, and all of the like nature, are solved, by showing the different senses of the words, terms, or phra

ses.

Bnt where such gross equivocations and ambiguities appear in arguments, there is little danger in imposing on ourselves or others; the greatest danger, and what we are perpetually exposed to in reasoning, is, where the two senses or significations of one term are near a-kin, and not plainly distinguished; and yet are sufficiently different in their sense to lead us into great mistakes, if we are not watchful. And, indeed, the greatest part of controversies, in the sacred or civil life, arise from the different senses that are put upon words, and the different ideas conveyed by them.

SOPHORA, in botany, a genus of the Decandria Monogynia class and order. Natural order of Papilionacea or Leguminosæ. Essential character: calyx fivetoothed, gibbous above; corolla papilionaceous, with the wings of the same length with the standard; legume. There are twenty-five species.

SORBUS, in botany, mountain-ash, a genus of the Icosandria Trigynia class and order. Natural order of Pomacez. Rosacea, Jussieu. Essential character: calyx five-cleft; petals five; berry inferior; three-seeded. There are three species.

SOREX, the shrew, in natural history, a genus of Mammalia of the order Feræ. Generic character: in the upper jaw two front teeth long and bifid; in the lower two or four, the intermediate ones shorter; several tusks on each side; grinders cuspidated. This genus of animals is most nearly allied to that of the mouse. Its teeth, however, constitute an important variation, and class it rather with the carnivorous tribes. There are seventeen species, of which the following most deserve attention. S. araneus, or the fetid shrew, is found throughout Europe and the north of Asia, and inhabits fields, gardens and out-houses, and measures about two inches and a half in length, exclusively of its tail. It is distinguished from a mouse chiefly by a long and sharp snout. It breeds in holes under banks, feeds on roots and grain, as well as on every species of putrid animal substance, and has a very rank and disagreeable odour, whence it derives its designation.

S. moschatus, or the musky shrew, abounds in the north of Europe and Asia, and inhabits principally the river Volga, rarely appearing on land. It is about seven inches long to the tail, and of a cinereous brown colour. Its snout is extremely prolonged, and apparently cartilaginous. It feeds on worms, water-insects and leeches, and sometimes on vegetables. These animals are often observed swimming on rivers and lakes in large companies. On land their motions are particularly slow. They are destroyed in Russia, to be placed in drawers or chests, from which they effectually keep moths at a distance. See Mammalia, Plate XX. fig. 3.

S. radiatus, or the radiated shrew, is a native of Canada, and is remarkable for having on the extremity of its snout a circle of sharp pointed processes, somewhat like the radius of a boot-spur; for

having its tail most curiously knotted, somewhat resembling what are called Queen's garters; and for having its feet with five toes, each covered with scales. It burrows like the mole, but is seen far more frequently above ground. See Mainmalia, Plate XX. fig. 2.

S. cæruleus, or the perfuming shrew, is found in India, and is stated to leave an intolerable musky scent on every substance over which it passes; and it has been asserted by gentlemen of respectability, that a corked bottle of wine has been so completely penetrated by this ef fluvium, as totally to spoil the liquor. The great strength and subtlety of the perfume are, at all events, unquestionable. This animal prefers rice to almost all other food, living chiefly in the rice fields, but occasionally entering houses.

S. exilis, or the pigmy shrew, abounds in Siberia, is shaped and coloured like the common shrew, and is noticed here for being probably the very smallest of European quadrupeds, being about half a dram' only in weight. See Mammalia, Plate XX. fig. 1.

SORITES, in logic, a species of reasoning, in which a great number of proposi tions are so linked together, that the predicate of the one becomes continually the subject of the next following, till at last a conclusion is formed, by bringing together the subject of the first proposition and the predicate of the last; such is the following argument, "God is omnipotent; an omnipotent being can do every thing possible; a being that can do every thing possible, can do whatever involves not a contradiction; therefore, God can do whatever involves not a contradiction." This combination of propositions may be continued to any length we please, without in the least weakening the ground upon which the conclusion rests; and the reason is, because the sorites may be resolved into as many simple syllogisms as there are middle terms in it: and the conclusion of the last syllogism is universally found to be the same with the conclusion of the sorites.

SOUND, or HEARING, sense of. The sense of sight is effected by rays of light, proceeding from the different objects to the retina. The sense of feeling is effected by the contact of its various objects with the body, or by the vigorous or unsound state of the parts of the body. The sense of taste is affected by certain particles of substances which are dissolved by the saliva, and thus brought into contact with the organs of taste. The sense

of smell is affected by particles which various substances are continually sending into the air, and which impress the membrane which lines the cavity and bones of the nose. The sense of hearing is affected by the pulsations or vibrations of the air, which are caused by its own expansion, or by the vibrations of sounding bodies. These sensations, or vibrations in the air, are called sounds, as are also the sensations which they produce. The organ of hearing is much more complicated and much less understood, than that of sight. We shall here give a very general account of it, and refer those who wish for further information to the article ANATOMY. The external ear collects and modifies sounds; and by a long channel communicates them to the internal ear: this consists, in the first place, of what is called the drum of the ear, which is a small cavity, closed towards the opening of the ear by a delicate membrane. In the drum are three or four very small bones, furnished with muscles and joints. From the drum are several openings, one of which is to the mouth; the others communicate into the different recesses of the ear. One of these leads into the labyrinth, which consists, first, of a small irregular cavity, next of three semi-circular canals, and lastly of a winding spiral canal, not unlike some sea shells. All these parts of the cavity are lined with a very delicate membrane, and filled with a watery fluid, which conveys to the portions of the nerve in contact with it, the vibrations received from the membrane which separates the labyrinth from the drum of the ear. The vibrations of the air act upon the drum, and thus set in motion the series of small bones in the cavity of the drum; these communicate the vibrations to the membrane which separates the drum from the labyrinth, and this (as before mentioned) produces vibrations in the watery fluid, in the several parts of the labyrinth, and conveys to the nervous branches, which line the labyrinth, the vibrations originally produced on the drum. The mechanism is complicated, but what we understand must increase our reverential admiration of the skill which produced it.

There are colours which of themselves, without associated ideas, are agreeable to the sight; so it is reasonable to believe, that there are sounds which of themselves, without associated deas, are agreeable to the ear. This is authorized also by direct experience. All moderate and tolerably uniform sounds please young children; and during the whole of life,

various combined and simple sounds give pleasure to the mind, without any reference to the associated ideas. Hence it appears that the pleasures of hearing aid considerably in the formation, or at least in the increase, of the mental plea sures indeed in connection with those of sight, they constitute nearly the whole of the pleasures of sublimity and beauty. It is a well known fact, that the ideas left by the sensations of sight are the most vivid and distinct of any next to these are those produced by the sensation of bearing. Few can form a distinct, certainly not a vivid, conception of the feel of any substance, which has present ed sensations through the medium of the touch, and not many more can of a taste, or of a smell, though thinking of particular taste produces considerable effusion of the saliva. Of objects of the sight we are able to form conceptions, which often approach in vividness and distinctness to the original sensations, and which sometimes overpower those actually present in the mind, so as in many cases to lead to the belief of a real object, and consequently to lead to the belief of apparitions, &c. Few, we believe, possess the power of forming conceptions of sounds nearly equal in vividness and distinctness with the original sensation; but they are frequently perceptible. After we have heard music, or conversed much with a person, trains of audible ideas frequently pass in the mind. So, when we are thinking or reading slowly and carefully, we can generally trace the relics of the audible impressions of the words suggested by the thoughts, or the sight of the letters; that is, we have faint conceptions of the sounds of these words.

The necessity of hearing to man, considered as a social being, is obvious; its importance to him, considered as a being whose pleasures and pains are by degress to be purely mental, is not inferior. The means of knowledge are greatly diminished by the loss of sight; but the loss of sight only impedes the progress of the mind from sensation to thought and feeling. Those who have never heard have much greater disadvantages to undergo. Their deficiencies can never be fully supplied. Words, as Hartley suggests, are highly important, and even necessary, to the full improvement of intellect, and the enlargement of the affections; and therefore the car is of much more importance to us, as spiritual beings, than the eye.

To illustrate the cause of sound, it is to be observed, 1st. That à motion is ne

cessary in the sonorous body for the production of sound. 2dly, That this motion exists first in the small and insensible parts of the sonorous bodies, and is excited in them by their mutual collision against each other, which produces the tremulous motion so observable in bodies that have a clear sound, as bells, musical chords, &c. 3dly, That this motion is communicated to, or produces a like motion in the air, or such parts of it as are fit to receive and propagate it. Lastly, That this motion must be communicated to those parts that are the proper and immediate instruments of hearing. Now that motion of a sonorous body, which is the immediate cause of sound, may be owing to two different causes; either the percussion between it and other hard bodies, as in drums, bells, chords, &c. or the beating and dashing of the sonorous body and the air immediately against each other, as in flutes, trumpets, &c. But in both these cases, the motion, which is the consequence of the mutual action, as well as the immediate cause of the sonorous motion which the air converys to the ear, is supposed to be an invisible, tremulous, or undulating motion, in the small and insensible parts of the body.

The sonorous body having made its impression on the contiguous air, that impression is propagated from one particle to another, according to the laws of pneumatics. A few particles, for instance, driven from the surface of the body, push or press their adjacent particles into a less space; and the medium, as it is thus rarefied in one place, becomes condensed in the other; but the air thus compressed in the second place is, by its elasticity, returned back again, both to its former place and its former state; and the air contiguous to that is compressed; and the like obtains, when the air less compressed, expanding itself, a new compression is generated. Therefore, from each agitation of the air there arises a motion in it, analogous to the motion of a wave on the surface of the water, which is called a wave or undulation of air. In each wave, the particles go and return back again through very short equal spaces; the motion of each particle being analogous to the motion of a vibrating pendulum, while it performs two oscillations; and most of the laws of the pendulum, with very little alteration, being applicable to the former.

Sounds are as various as are the means that concur in producing them. The

Euler is of opinion, that no sound making fewer vibrations than 30 in a second, or more than 7520, is distinguishable by the human ear. According to this doctrine, the limit of our hearing, as to acute and grave, is an interval of eight octaves. The velocity of sound is the same with that of the aerial waves, and does not vary much, whether it go with the wind or against it. By the wind indeed a certain quantity of air is carried from one place to another; and the sound is accelerated while its waves move through that part of the air, if their direction be the same as that of the wind. But as sound moves vastly swifter than the wind, the acceleration it will hereby receive is but inconsiderable; and the chief effect we can perceive from the wind is, that it increases and diminishes the space of the waves, so that by help of it the sound may be heard to a greater distance than otherwise it

would.

That the air is the usual medium of sound, appears from various experiments in rarefied and condensed air. In an unexhausted receiver, a small bell may be heard to some distance; but when exhausted, it can scarce be heard at the smallest distance. When the air is condensed, the sound is louder in proportion to the condensation, or quantity of air crowded in; of which there are many instances in Hauksbee's experiments, in Dr. Priestley's, and others. Besides, sounding bodies communicate tremors to distant bodies; for example, the vibrating motion of a musical string puts others in motion, whose tension and quantity of matter dispose their vibrations to keep time with the pulses of air, propagated from the string that was struck. Galileo explains this phenomenon, by observing, that a heavy pendulum may be put in

VOL. XI.

motion by the least breath of the mouth, provided the blasts be often repeated. and keep time exactly with the vibrations of the pendulum; and also by the like art in raising a large bell.

It is not air alone that is capable of the impressions of sound, but water also; as is manifest by striking a bell under water, the sound of which may plainly enough be heard, only not so loud, and also a fourth deeper, according to good judges in musical notes. And Mersenne says, a sound made under water is of the same tone or note as if made in air, and heard

under the water. The velocity of sound, or the space through which it is propagated in a given time, has been very differently estimated by authors who have written concerning this subject. Roberval states it at the rate of 560 feet in a second;

Gassendus at 1473; Mersenne at 1474; Duhamel, in the History of the Academy of Sciences at Paris, at 1338; Newton at 968; Derham, in whose measure Flamstead and Halley acquiesce, at 1142. The reason of this variety is ascribed by Derham, partly to some of those gentlemen using strings and plummits instead of regular pendulums; and partly to the too small distance between the sonorous body and the place of observation; and partly to no regard being had to the winds. But by the account since published by M. Cassini de Thury, in the Memoirs of the Royal Academy of Sciences at Paris, 1738, where cannon were fired at various as well as great distances, under many varieties of weather, wind, and other circumstances, and where the measures of the different places had been settled with the utmost exactness, it was found that sound was propagated on a medium, at the rate of 1038 French feet in a second of time. But the French foot is in proportion to the English as 15 to 16: and consequently 1038 French feet are equal to 1107 English feet. Therefore the difference of the measures of Derham

and Cassini is 35 English feet, or 33 French feet, in a second. The medium velocity of sound, therefore, is nearly at the rate of a mile, or 5280 feet, in 42 seconds, or a league in 14 seconds, or 13 miles in a minute. But sea miles are to land miles nearly as 7 to 6; and therefore sound moves over a sea mile in 51 seconds nearly, or a sea league in 16 seconds. Further, it is a common observation, that persons in good health have about 75 pulsations, or beats of the artery at the wrist, in a minute; conse. Сс