Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/88

 MOT

M O U

Si quantity of motion, which is collected by taking the fum " of the motions directed towards the fame parts, and the " difference of thofe that are directed to contrary parts, fuf- " fers no change from the aft ion of bodies among them- " felves." Newt. Princip. lib. I.

Some philofophers, after Defcartes, have fuppofed the prefer - vation of the fame force or vis viva. See the articles Force,. and Vis Viva.

But this holds only in elaftic bodies, when there is a fhock ; and hence thofe philofophers have been led to maintain, that all bodies were elaftic, at Ieaft in their elements, and that an inflexible body was impofllble, being repugnant to the law of continuity. See the article Continuity.

Motion of the Limbs. See the article Lime.

Motion, in the antient mufic, was ufed to fignify the tranfition of the voice, from an acute to a grave found ; or the contrary. This they exprelTed by m™ totq» xmwUi. IFalliss Append. ad Ptolem. Harmonic, p. 153. See the article Locus. Meibomius tranflates it, moveri hi loco.

Motion, in the manege. A horfe is faid to have a pretty Mo- tion^ when he moves and bends his fure-legs with great eafe and freedom upon the manege. But if a horfe. trots right out, and keeps his body ftraight, and his head high, and bends his fore-legs handfomely, then to fay he has a pretty Motion with him, implies the liberty of aftion of the forehead.

Mufcular Motion. Dr. Browne Langriih endeavours to prove that the blood has no immediate effeft in mufcular Motion, by experiments of tying the crural and carotid arteries of dogs, who did not thereby lofe the aftion of any mufcles. He grants however, that when all the blood is intercepted, mufcular Motion ceafes in a few minutes. The chief ufe or the blood towards mufcular Motion^ is to keep the fibres warm, fupple, diftended, and ready for the influx of animal (pints in- to them, and by its Motion to aflitt theirs. The mufcular fibres are little hollow cylinders, not divided into cells ; the animal fpirits are near a-kin, or analogous to fpirit of fal ammoniac, &c, and therefore) whenever they fly ,from the nerves into the mufcular fibres, they will increafe the attraftive quality of their component particles towards each other, fo as to make them run nearer together, which will occafion the coats of the fibres to be both thicker and fhorter, and the mufcle will be coritrafted in all its dimenftons. The animal fpirits are too fubtile to be fixed, and therefore imme- diately make their efcape through the fibres, and leave them in the fame ftate they found them in, as foon as the fupply by the nerves is difcontinued. There is a difference in the mecban'iGn of the nerves fent to the mufcles, which aft by the influence of the mind, from thole of the mufcles which are faid to perform involuntary motions, the latter having no hindrance to the courfe of the animal fpirits, unlefs fometimes the parts through which they pafs have influence on them ; whereas the nerves, which ferve the mufcles of voluntary motion, have fome little conftriftions at their extremities, or elfewhere, which hinders the courfe of their fluids, except when their refiftance is overcome by the momentum of the fpirits being increafed by the will. The ufe of the ganglions is to prevent any communication of motion from one nerve to another, whereby in a ftate of health, fenfation is always performed diftinftly. Eff. on Mu'fc. Motion. Dr. Stuart having cut off the head of a frog, obferved, that upon thrufting a probe into the medulla fp'tnalis, the mufcles of the body were brought into convulfive contractions. And that the fame happened to the mufcles of the head, when the probe was thruft into the brain. From which he concludes, that the brain and nerves contribute to mufcular Motion in a high degree. Next he laid bare the crural artery, vein, and nerve of a dog, and placing a thread parallel to them, made two ligatures on them, at four inches diitance from each other j then cutting the vefTels through, beyond the ligatures, lie took them out, and obferved, that the nerve did notcontraft, though the blood-veflels loft three eighth parts of their length. From whence he infers, that what the nerves contribute in mufcular Motion, cannot arife from, or be owing to elafticky, but to the fluid they contain, which can be no other than a pure elementary water. Phil. Tranf. N°. 424. §. 5.

Rythmical Motions, a phrafe ufed by Voflius, and other wri- ters on the antient rythm, to exprefs thofe motions which were made ufe of in the Greek and Roman entertainments to convey the ideas of the poet, or to aflift mufic in rouzing the paflions. Thefe not only had great force when joined with founds, but even without any voice or found they could move the paflions in the fpeftators, more than many of the beft orators of the times could do with their moft laboured difcourfes.

Rofcius, the ftage-player fo famous in their pantomimes which were all dumb fhew, was fo excellent at exprefllon by thefe rythmical Motions, or geftures, that Cicero and he being co- temporaries' there were many difputes between them, which could vary the fame fentence moft; ; the one ufmg all the power of words, the other being confined to geftures alone.

Motion, Moto, or Movimento, in the Italian mufic, has many fignifications \ fometimes it means only a Motion or paffa^e from one note to another, at whatfoever diftance, as a fecond, third, or any other interval ; and is the fame whether the in-

termediate degrees (if there are any) be founded or only the extremes of them, as the firft and laft found of any given in- terval. Sometimes it regards the quicknefs and flownefs of fuch motions, as a brifk, flow, lively, or languid motion ; and in this fenfe it is ufed with regard to minuets, gavots, fa- rabands, cs'c. See each article in its proper place, and Mo- tion, Cycl.

But the moft common, and indeed the moft important accep- tation of the word, is with refpeft to harmony j thofe above defcribed only regarding melody. See the articles Melody, and Harmony, Cycl.

With regard to harmony, it is the comparing the manner Wherein an upper or treble part moves trom one found to another, with that wherein a lower or bafs-part moves ; this is to be done three ways. The firft is when the upper and lower parts move both the fame way, either upwards or down- wards, and is called Moto retto. The fecond is when in com- paring the upper with the lower part, the one afcends while the other defcends, or e contra, and hence called Moto con- trario. The laft is when one of the parts holds out, or con- tinues a found, while the other rifes or falls on any note whatfoever; and this is called Moto obliquo. Vid. BroJJ". Muf. Dift. in voc.

MOTIVE is fome:imes applied to that faculty of the human mind, by which we purfue good and avoid evil. Thus Mobbes diftinguilhes the faculties of the mind into two forts, the cognitive, and ?notive. Human Nat. p. 4. edit. 1651. Seethe article Cognitive.

MOTOS, (Cycl.) in the materia medica of the antients, a name given by Galen and others to a kind of Caflia bark, the beft and fineft that has been ufed at any time. The antients were very fond of this drug, and ranged it according to its diffe- rent goodnefs into fevefal forts.

MOL'CHEROLLE, in zoology, the name of a fmall bird of the iize of the fparrow, and of the fame colour, but longer bodied ; its wings are of a dufkier colour than the reft of its body ; and its head is variegated with very fmall blackifh fpots. Its throat and belly are white, but the throat and the fides of the breaft and belly have a faint reddiihnefs ; the beak is black, ftrait and ridged, fo as to appear triangular. It feeds on flies and other infefts, and is common in gardens and orchards in many parts of England, though it has no Englilh name. It is con- founded by the common people with the common white throat, but differs from it in that its tail is all of one colour, whereas the white-throat's is variegated. It fomewhat refembles alfo the beccifago, or petty-chaps, but differs from it in having no grecnifh colour, and in its bill being ridged and triangular. Ray's Ornith'ol. p. 159- See the article Beccifago;

MOVING Force. See the articles Force, and Vis Vivai

MOULD (Cycl.) — Moulds.; in na-tural hifrory, are defined to be foilile bodies compofed of diifimilar particles of a loofe foft texture, fomewhat duftile while moift, compofed of argilace- ous particles feparated by fand or the gritt of ftone, and ufu- ally found mixed with the putrified remains of vegetable and animal fubftances.

Of this clafs of bodies there are two genera : 1. The thrup- ' tomichthes or Moulds of a lax friable texture. And, 2. The gloromichthes, which are of a more tough and vifcid texture. HiWs Hift. of Foft". For the feveral fpecies of vegetable Moulds, fee the articles Thru ptomicht he s, and Glo- romichthes.

The goodnefs of Mould, for the gardeners purpofes, is known by the fight, fmell, and touch.

Thofe Moulds are accounted beft which are of a bright brown or hazily Colour.. This is always the colour of the beft loams, and other natural earths ; and this is judged the better, if the earth cut tolerably eafily, and does not ftick and cling to the fpade, but is light, friable, and falls in fmall clods ; and is fuch as naturally neither chaps and cracks in dry weather, nor turns to' mortar in Wet. Next to thefe the dark grey and ruffe t Moulds are accounted beft ; and the worft: of all are the light and dark afh-colour ; thefe are ufually found on heaths and commons. The clear tawny Mould is neither by any means to be preferred; but that of a yellowifh red is accounted the worft of all ; this is commonly found in wild and wafte places, and feldom produces any thing naturally but furz and fern. Miller's Gardeners Dift.

All that lands give us to judge of them by from the fmell, is, that the beft after rain, and after digging up, emit a good and pleafing fcent : But by the touch they may be judged of with confiderable accuracy ; for by this may be known whether they are too fandy or too clayey ; and whether they be tender, fatty-, deterfive, and flippery ; or more harfh, gritty, porous and friable. What we are to judge beft by the touch, is the middle nature between the extremes on either fide, fuch as will eafily diflblve and break, and being made of a juft propor- tion of fand and clay, will not ftick to the fpade or fingers af- ter every light fhower of rain.

To analize Moidd by means of water, wafli it thoroughly in warm water in large quantities, and filtrate the liquor. Eva- porate this to a confiderable degree of concentration, and it is manifeftly of a faline tafte, but making no alteration in fy rup of violets ; therefore the fait it contains is neither acid nor al- kaline, but neutral. This analyfis purfued farther, the parti- cles