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liave obscured all others, yet they know but little magnet when armed with steel, for it excites in about it, and commit many errors in its estimate the steel a power of adhering to steel, as a homo

Let the eighth be that which we term the mo-geneous substance, the power of the magnet tion of lesser congregation, by which the homoge- breaking through the sluggishness of the steel. neous parts in any body separate themselves from With regard to the assistance of motion, it is seen the heterogenous and unite together, and whole in wooden arrows or points, which penetrate more bodies of a similar substance coalesce and tend deeply into wood than if they were tipped with towards each other, and are sometimes congre- iron, from the similarity of the substance, the gated, attracted, and meet, from some distance ; swiftness of the motion breaking through the thus, in milk the cream rises after a certain time, sluggishness of the wood; of which two last and in wine the dregs and tartar sink; which experiments we have spoken above, in the aphoeffects are not to be attributed to gravity and rism on clandestine instances.* levity only, so as to account for the rising of some The confinement of the motion of lesser conparts and the sinking of others, but much more to gregation, which arise from the power of the the desire of the homogeneous bodies to meet and predominant body, is shown in the decomposition unite. This motion differs from that of need in of blood and urine by cold. For, as long as these two points: 1st. Because the latter is the stimu- substances are filled with the active spirit, which lus of a malignant and contrary nature ; whilst in regulates and restrains each of their component this of which we treat, (if there be no impediment parts, as the predominant ruler of the whole, the or restraint,) the parts are united by their affinity, several different parts do not collect themselves although there be no foreign nature to create a separately on account of the check ; but as soon struggle; 2dly. Because the union is closer and as that spirit has evaporated, or has been choked more select. For, in the other motion, bodies by the cold, then the decomposed parts unite, which have no great affinity unite, if they can but according to their natural desire. Hence, it avoid the hostile body, whilst in this, substances happens, that all bodies which contain a sharp which are connected by a decided kindred resem- spirit (as salts, and the like) last, without deblance, come together and are moulded into one. composition, owing to the permanent and duraIt is a motion existing in all compound bodies, ble power of the predominating and imperious and would be readily seen in each, if it were spirit. not confined and checked by the other affec- The confinement of the motion of lesser contions and necessities of bodies which disturb the gregation, which arises from external motion, is union.

very evident in that agitation of bodies, which This motion is usually confined in the three preserves them from putrefaction. For all putrefollowing manners: by the torpor of the bodies ; faction depends on the congregation of the homoby the power of the predominating body; by ex- geneous parts, whence, by degrees, there ensues ternal motion. With regard to the first, it is a corruption of the first form, (as it is called,) and certain that there is more or less sluggishness in the generation of another. For, the decompositangible bodies, and an abhorrence of locomotion : tion of the original form, which is itself the union so that, unless excited, they prefer remaining con- of the homogeneous parts, precedes the putrefactented with their actual state, to placing them- tion, which prepares the way for the generation selves in a better position. There are three of another. This decomposition, if not inter: means of breaking through this sluggishness : rupted, is simple; but if there be various obstaheat; the active power of a similar body; vivid cles, putrefactions ensue, which are the rudiments and powerful motion. With regard to the first of a new generation. But, if (to come to our heat is, on this account, defined as that which present point) a frequent agitation be excited, by separates heterogeneous, and draws together ho- external motion, the motion towards union (which mogeneous substances ; a definition of the peri- is delicate and gentle, and requires to be free from patetics, which is justly ridiculed by Gilbert, all external influence) is disturbed, and ceases; who says it is as if one were to define man to be which we perceive to be the case in innumerable that which sows wheat and plants vineyards ; instances. Thus, the daily agitation or flowing being only a definition deduced from effects, and of water prevents putrefaction; winds prevent those but partial. But, it is still more to be the air from being pestilent; corn, turned about blamed, because those effects, such as they are, and shaken in granaries, continues clean; in are not a peculiar property of heat, but a mere short, every thing which is externally agitated, accident, (for cold, as we shall afterwards show, will, with difficulty, rot internally. does the same,) arising from the desire of the ho- We must not omit that union of the parts of taogeneous parts to unite; the heat then assists bodies which is the principal cause of induration them in breaking through that sluggishness, and desiccation. When the spirit or moisture, which before restrained their desire. With re- which has evaporated into spirit, has escaped gard to the assistance derived from the power of a similar body, it is most conspicuous in the

from a porous body, (such as wood, bone, parch- that which is opposed to the motion of lesser corment, and the like,) the thicker parts are drawn gregation, by which bodies, with a kind of antitogether, and united with a greater effort, and in- pathy, avoid and disperse, and separate themi: duration or desiccation is the consequence; and selves from, or refuse to unite themselves with this we attribute not so much to the motion of others of a hostile nature. For, although this connexion, (in order to prevent a vacuum,) as to may sometiines appear to be an accidental mothis motion of friendship and union.

tion, necessarily attendant upon that of the lesser Union from a distance is rare, and yet is to be congregation, because the homogeneous parts met with in more instances than are generally cannot unite, unless the heterogeneous be first observed. We perceive it when one bubble dis- removed and excluded; yet it is still to be classed solves another, when medicines attract humours separately, and considered as a distinct species, from a similarity of substance, when one string because, in many cases, the desire of avoidance moves another in unison with it on different in- appears to be more marked than that of union. struments, and the like. We are of opinion that It is very conspicuous in the excrements of this motion is very prevalent also in animal spi- animals, nor less, perhaps, in objects odious to rits, but are quite ignorant of the fact. It is, particular senses, especially the smell and taste. however, conspicuous in the magnet, and mag- For a fetid smell is rejected by the nose, so as to netized iron. Whilst speaking of the motions produce a sympathetic motion of expulsion at the of the magnet, we must plainly distinguish them, mouth of the stomach; a bitter and rough taste for there are four distinct powers or effects of the is rejected by the palate or throat, so as to produce magnet which should not be confounded, although a sympathetic concussion and shivering of the the wonder and astonishment of mankind has head. This motion is visible also in other cases. classed them together. 1. The attraction of the Thus it is observed in some kinds of antiperistasis, magnet to the magnet, or of iron to the magnet, as in the middle region of the air, the cold of or of magnetized iron to iron. 2. Its polarity which appears to be occasioned by the rejection towards the north and south, and its variation. of cold from the regions of the heavenly bodies; 3. Its penetration through gold, glass, stone, and and also in the heat and combustion observed in all other substances. 4. The communication of subterraneous spots, which appear to be owing power from the mineral to iron, and from iron to to the rejection of heat from the centre of the iron, without any communication of the sub- earth. For heat and cold, when in small quantistances. Here, however, we only speak of the ties, mutually destroy each other, whilst in larger first. There is also a singular motion of attrac- quantities, like armies cqually matched, they retion between quicksilver and gold, so that the move and eject each other in open conflict. It is gold attracts quicksilver even when made use of said, also, that cinnamon and other perfumes in ointment, and those who work surrounded by retain their odour longer when placed near privies the vapours of quicksilver are wont to hold a and foul places, because they will not unite and piece of gold in their mouths, to collect the exha- mix with stinks. It is well known that quicklations, which would otherwise attack the heads silver, which would otherwise reunite into a com. and bones, and this piece soon grows white.* plete mass, is prevented from so doing by man's Let this suffice for the motion of lesser congre- spittle, pork, lard, turpentine, and the like, from gation.

the little affinity of its parts with those substances, Let the ninth be the magnetic motion, which so that when surrounded by them it draws itself although of the nature of that last mentioned, yet, back, and its avoidance of these intervening obwhen operating at great distances, and on great stacles is greater than its desire of reuniting itself masses, deserves a separate inquiry, especially to its homogeneous parts; which is what they if it neither begin in contact, as most motions term the mortification of quicksilver. Again, the of congregation do, nor end by bringing the sub- difference in weight of oil and water is not the stances into contact, as all do, but only raise only reason for their refusing to mix, but it is also them, and make them swell without any further owing to the little affinity of the two, for spirits effect. For if the moon raise the waters, or of wine, which are lighter than oil, mix very cause moist substances to swell, or if the starry well with water. A very remarkable instance sphere attract the planets towards their apogees, of the motion in question is seen in nitre, and or the sun confine the planets Mercury and Venus crude bodies of a like nature, which abhor flame, to within a certain distance of his mass;t these as may be observed in gunpowder, quicksilver, motions do not appear capable of being classed and gold. The avoidance of one pole of the under either of those of congregation, but to be, magnet by iron is not, (as Gilbert has well obas it were, intermediately and imperfectly congre- served,) strictly speaking, an avoidance, but a gative, and thus to form a distinct species. conformity, or attraction to a more convenient Let the tenth motion be that of avoidance, or situation.

Let the eleventh motion be that of assimilation, Query. 4 Observe this approximation to Newton's theory! or self-multiplication, or simple generation, by

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which latter term we do not mean the simple motions, bodies appear to aim at the mere pre. generation of integral bodies, such as plants or servation of their nature, whilst in this they at. animals, but of homogeneous bodies. By this tempt its propagation. motion homogeneous bodies convert those which Let the twelfth motion be that of excitement, are allied to them, or, at least, well disposed and which appears to be a species of the last, and is prepared, into their own substance and nature. sometimes mentioned by us under that name. It Thus flame multiplies itself over vapours and is, like that, a diffusive, communicative, transioily substances, and generates fresh flame; the tive, and multiplying motion; and they agree reair over water and watery substances multiplies markably in their effect, although they differ in itself and generates fresh air ; the vegetable and their mode of action, and in their subject matter. animal spirit, over the thin particles of a watery The former proceeds imperiously, and with anor oleaginous spirit contained in its food, multi-thority; it orders and compels the assimilated to plies itself and generates fresh spirit; the solid be converted and changed into the assimilating parts of plants and animals, as the leaf, flower, body. The latter proceeds by art, insinuation, the flesh, bone, and the like, each of them assi- and stealth, inviting and disposing the excited inilate some part of the juices contained in their towards the nature of the exciting body. The food, and generate a successive and daily sub- former both multiplies and transforms bodies and stance. For let none rave with Paracelsus, who substances; thus a greater quantity of flame, air, (blinded by his distillations) would have it, that spirit, and flesh is formed; but in the latter, the nutrition takes place by mere separation, and powers only are multiplied and changed, and that the eye, nose, brain, and liver, lie concealed heat, the magnetic power, and putrefaction, in in bread and meat, the root, leaf, and flower, in the above instances, are increased. Heat does the juice of the earth ; asserting that just as the not diffuse itself, when heating other bodies, by artist brings out a leaf, flower, eye, nose, hand, any communication of the original heat, but only foot, and the like, from a rude mass of stone or by exciting the parts of the heated body to that wood, by the separation and rejection of what is motion which is the form of heat, and of which superfluous; so the great artist within us brings we spoke in the first vintage of the nature of out our several limbs and parts by separation heat. Heat, therefore, is excited much less and rejection. But to leave such trifling, it is rapidly and readily in stone or metal, than in air, most certain that all the parts of vegetables and on account of the inaptitude and sluggishness animals, as well the homogeneous as organic, of those bodies in acquiring that motion, so that first of all attract those juices contained in their it is probable that there may be some substances, food, which are nearly common, or at least not towards the centre of the earth, quite incapable very different, and then assimilate and convert of being heated, on account of their density, them into their own nature. Nor does this as- which may deprive thein of the spirit by which siinilation, or simple generation, take place in the motion of excitement is usually commenced. animated bodies only, but the inanimate also Thus, also, the magnet creates in the iron a new participate in the same property, (as we have ob- disposition of its parts, and a conformable motion, served of flame and air,) and that languid spirit, without losing any of its virtue. So the leaven which is contained in every tangible animated sub- of bread, yeast, rennet, and some poisons, excite stance, is perpetually working upon the coarser and invite successive and continued motion in parts, and converting them into spirit, which af- dough, beer, cheese, or the human body; not so terwards is exhaled, whence ensues a diminution much from the power of the exciting, as the preof weight, and a desiccation of which we have disposition and yielding of the excited body. spoken elsewhere.* Nor should we, in speak- Let the thirteenth motion be that of impression, ing of assimilation, neglect to mention the accres which is also a species of motion of assimilation, tion which is usually distinguished from aliment, and the most subtile of diffusive motions. We and which is observed when mud grows into a have thought it right, however, to consider it as mass between stones, and is converted into a a distinct species, on account of its remarkable stony substance, and the scaly substance round difference from the two last. For the simple mothe teeth is converted into one no less hard than tion of assimilation transforms the bodies themthe teeth themselves; for we are of opinion that selves, so that if you remove the first agent, you there exists in all bodies a desire of assimilation, diminish not the effect of those which succeed; as well as of uniting with homogeneous masses. thus, neither the first lighting of flame, nor the Each of these powers, however, is confined, first conversion into air, are of any importance to although in different manners, and should be the flame or air next generated. So, also, the diligently investigated, because they are con motion of excitement still continues for a consi. nected with the revival of old age. Lastly, it is derable tin after the removal of the first agent. worthy of observation, that in the nine preceding as in a heated body on the removal of the original

heat, in the excited iron on the removal of the * See the citing instances, Aphorism 40. magnet, and in the dough on the removal of the

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leaven. But the motion of impression, although may be put, for it must also revolve round certain diffusive and transitive, appears, nevertheless, to poles, and why should they be placed where they depend on the first agent, so that, upon the re-are, rather than elsewhere? The polarity and moval of the latter, the former immediately fails variation of the needle come under our present and perishes ; for which reason also it takes effect head. There is also observed in both natural in a moment, or at least a very short space of time. and artificial bodies, especially solids rather than We are wont to call the two former motions the fluids, a particular collocation and position of motions of the generation of Jupiter, because parts, resembling hairs or fibres, which should be when born they continue to exist; and the latter, diligently investigated, since, without a discovery the motion of the generation of Saturn, because of them, bodies cannot be conveniently controlled it is immediately devoured and absorbed. It or wrought upon. The eddies observable in may be seen in three instances; 1. In the rays of liquids by which, when compressed, they suclight; 2. In the percussions of sounds; 3. In cessively raise different parts of their mass before magnetic attractions as regards communication. they can escape, so as to equalize the pressure, is For, on the removal of light, colours and all its more correctly assigned to the motion of liberty. other images disappear, as, on the cessation of the Let the fifteenth motion be that of transmission, first percussion and the vibration of the body, or of passage, by which the powers of bodies are sound soon fails; and although sounds are agi- more or less impeded or advanced by the medium, tated by the wind, like waves, yet it is to be ob- according to the nature of the bodies and their served, that the same sound does not last during effective powers, and also according to that of the whole time of the reverberation. Thus, when the medium. For one medium is adapted to a bell is struck, the sound appears to be continued light, another to sound, another to heat and cold, for a considerable time, and one might easily be another to magnetic action, and so on with regard led into the mistake of supposing it to float and to the other actions. remain in the air during the whole time, which Let the sixteenth be that which we term the is most erroneous. For the reverberation is not royal or political motion, by which the predomione identical sound, but the repetition of sounds; nant and governing parts of any body check, which is made manifest by stopping and confining subdue, reduce, and regulate the others, and force the sonorous body; thus, if a bell be stopped and them to unite, separate, stand still, move, or as. held tightly, so as to be immovable, the sound sume a certain position, not from any inclination fails, and there is no further reverberation; and if of their own, but according to a certain order, and a musical string be touched after the first vibra- as best suits the convenience of the governing tion, either with the finger, (as in the harp,) or a part, so that there is a sort of dominion and civil quill, (as in the harpsichord,) the sound immedi- government exercised by the ruling part over its ately ceases. If the magnet be removed, the iron subjects. This motion is very conspicuous in talls. The moon, however, cannot be removed the spirits of animals, where, as long as it is in from the sea, nor the earth from a heavy falling force, it tempers all the motion of the other parts. body, and we can, therefore, make no experiment It is found in a less degree in other bodies, as we upon thein, but the case is the same.

have observed in blood and urine, which are not Let the fourteenth motion be that of configura- decomposed until the spirit, which mixed and tion or posilion, by which bodies appear to desire retained their parts, has been emitted or extina peculiar situation, collocation, and configuration guished. Nor is this motion peculiar to spirits with others, rather than union or separation. This only, although in most bodies the spirit predomiis a very abstruse motion, and has not been well nates, owing to its rapid motion and penetration; investigated; and, in some instances, appears to for the grosser parts predominate in denser booccur almost without any cause, although we be dies, which are not filled with a quick and active inistaken in supposing this to be really the case. spirit, (such as exists in quicksilver or vitriol,) l'or if it be asked, why the heavens revolve from so that unless this check or yoke be thrown off east to west, rather than from west to east, or why by some contrivance, there is no hope of any they turn on poles situated near the Bears, rather transformation of such bodies. And let not any than round Orion or any other part of the heaven, one suppose that we have forgotten our subjeci, such a question appears to be unreasonable, since because we speak of predominance in this clasthese phenomena should be received as determi- sification of motions, which is made entirely nate, and the objects of our experience. There with the view of assisting the investigation of are, indeed, some ultimate and self-existing phe- wrestling instances, or instances of predominomena in nature, but those which we have just nance. For we do not now treat of the general nuentioned are not to be referred to that class: for predominance of motions or powers, but of that we attribute them a certain harmony and con- of parts in whole bodies, which constitutes the sent of tne universe, which has not yet been pro- particular species here considered. perly observed. But if the motion of the earth Let the seventeenth motion be the spontaneous from west to east be allowed, the same question I motion of revolution, by which bodies having a

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l’ndency to move, and placed in a favourable Let the nineteenth and last motion be one situation, enjoy their peculiar nature, pursuing which can scarcely be termed a motion, and yet themselves and nothing else, and seeking as it is one; and which we may call the motion of were to embrace themselves. For bodies seem repose, or of abhorrence of motion. It is by this either to move without any limit, or to tend to- motion that the earth stands by its own weight, wards a limit, arrived at which, they either revolve whilst its extremes move towards the middle, not according to their peculiar nature, or rest. Those to an imaginary centre, but in order to unite. It which are favourably situated, and have a ten- is owing to the same tendency, that all bodies of dency to motion, move in a circle with an eternal considerable density abhor motion, and their only and unlimited motion; those which are favoura- tendency is not to move, which nature they piebly situated and abhor motion, rest. Those which serve, although excited and urged in a variety of are not favourably situated move in a straight ways to motion. But if they be compelled to ine, (as their shortest path,) in order to unite move, yet do they always appear anxious to rewith others of a congenial nature. This motion cover their former state, and to cease from motion, of revolution admits of nine differences; 1. With in which respect they certainly appear active, regard to the centre about which the bodies move; and attempt it with sufficient swiftness and ... The poles round which they move; 3. The rapidity, as if fatigued and impatient of delay. circumference or orbit relatively to its distance We can only have a partial representation of this from the centre; 4. The velocity or greater or less tendency, because with us every tangible subspeed with which they revolve; 5. The direction stance is not only not condensed to the utmost, of the motion, as from east to west, or the reverse; but even some spirit is added, owing to the action 6. The deviation from a perfect circle, by spiral and concocting influence of the heavenly bodies. lines at a greater or less distance from the centre ; We have now, therefore, exhibited the species 7. The deviation from the circle by spiral lines at or simple elements of the motions, tendencies, a greater or less distance from the poles; 8. The and active powers, which are most universal in greater or less distance of these spirals from each nature; and no small portion of natural science other; 9. And, lastly, the variation of the poles, has been thus sketched out. We do not, however, if they be movable; which, however, only af-deny that other instances can, perhaps, be added, lects revolution when circular. The motion in and our divisions changed according to some question is, according to common and long re- more natural order of things, and also reduced to ceived opinion, considered to be that of the hea- a less number; in which respect we do not allude venly bodies. There exists, however, with re- to any abstract classification, as if one were to gard to this, a considerable dispute between some say, that “ bodies desire the preservation, exaltaof the ancients as well as moderns, who have tion, propagation, or fruition of their nature;" attributed a motion of revolution to the earth. A or, that “motion tends to the preservation and inuch more reasonable controversy, perhaps, ex- benefit either of the universe, (as in the case of ists, (if it be not a matter beyond dispute,) whether those of resistance and connection,) or of extenthe motion in question on the hypothesis of the sive wholes, (as in the case of those of the greater earth's being fixed) is confined to the heavens, or congregation, revolution, and abhorrence of morather descends and is communicated to the air tion,) or in particular forms, as in the case of the and water. The rotation of missiles, as in darts, others. For, although such remarks be just, yet, inusket balls, and the like, we refer entirely to unless they terminate in matter and construction, the motion of liberty.

according to true definitions, they are speculative Let the eighteenth motion be that of trepida- and of little use. In the mean time, our classi. tim, to which in the sense assigned to it by fication will suffice, and be of much use in the astronomers) we do not give much credit; but in consideration of the predominance of powers, and our serious and general search after the tenden- examining the wrestling instances which concies of natural bodies, this motion occurs and stitute our present subject. appears worthy of forming a distinct species. It For, of the motions here laid down, some are is the motion of an (as it were) eternal captivity; quite invincible, some more powerful than others, when bodies, for instance, being placed not alto- which they confine, check, and modify; others gether according to their nature, and yet not extend to a greater distance, others are more imexactly ill, constantly tremble, and are restless, mediate and swift, others strengthen, increase, not contented with their position, and yet not and accelerate the rest. daring to advance. Such is the motion of the The motion of resistance is most adamanune heart and the pulse of animals, and it must ne- and invincible. We are yet in doubt whether cessarily occur in all bodies which are situated in such be the nature of that of connection; for we a mean state, between conveniences and inconve- cannot with certainty determine whether there be niences; so that being removed from their proper a vacuum, either extensive or intermixed with position, they strive to escape, are repulsed, and matter. Of one thing, however, we are satisfied, again continue to make the attempt.

that the reason assigned by Leucippus and Do Vol. III–53

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