1 Plafter rally appear in 10 or 15 days; after which the growth of the grafs will be fo great as to produce a large burden at the end of fix weeks after sowing. Plaftic. "It must be fown on dry land, not fubject to be overflown. I have fown it on fand, loam, and clay, and it is difficult to fay on which it has best answered, although the effect is fooner vifible on fand. It has been ufed as a manure in this ftate for upwards of twelve years. Its duration may, from the beft information I can collect, be estimated from feven to twelve years; for, like other manure, its continuance very much depends on the nature of the foil on which it is placed. "One of my neighbours fowed fome of his grafs ground fix years ago, another four years ago; a great part of my own farm was fown in May 1788. We regularly mow two crops, and pafture in autumn; no appearance of failure, the prefent crop being full as good as any preceding. I have this feafon mowed fifty acres of red clover, timothy grafs, white clover, &c. which was plaftered laft May, July, and September: many who faw the grafs eftimated the produce at two tons per acre, but I calculate the two crops at three tons. Several stripes were left in the different fields without plafter; these were in a measure unproductive, being fcarce worth mowing. In April 1788, I covered a piece of grafs land upwards of two inches thick with barn manure; in the fame worn-out field I fowed plafter, to contraft it with the dung. I mowed the dunged and plastered land twice last year and once this; in every crop the platter has produced the moft. You will remember, in all experiments with clover, to mix about one-third timothy grafs feed; it is of great advantage in ferving as a fupport for the clover; it very much facilitates the curing of clover, and when cured is a fuperior fodder. The plafter operates equally as well on the other graffes as on clover. Its effect is faid to be good on wheat, if fown in the fpring; but I cannot fay this from experience. On Indian corn I know its operation to be great; we ufe it at the rate of a tablefpoonful for a hill, put in immediately after dreffing. "From fome accurate experiments laft year made and reported to our Agricultural Society, it appears that nine bushels of additional corn per acre were produced by this method of ufing plafter." PLASTERING. See PARGETTING. PLASTIC, denotes a thing endowed with a formative power, or a faculty of forming or fashioning a mass of matter after the likeness of a living being. PLASTIC-Nature, a certain power by which, as an inftrument, many philofophers, both ancient and modern, have fuppofed the great motions in the corporeal world, and the various proceffes of generation and corruption, to be perpetually carried on. Among the philofophers of Greece, fuch a power was almoft univerfally admitted. It feems, indeed, to have been rejected only by the followers of Democritus and Epicurus, who talk as if they had thought gravity effential to matter, and the fortuitous motion of atoms, which they held to have been from eternity, the fource not only of all the regular motions in the univerfe, but alfo of the organization of all corporeal fyftems, and even of fenfation and intellection, in brutes and in men. It is needlefs to fay, that thofe men, whatever they might profefs, were in reality atheists; and Democritus, it is univerfally known, avowed his atheifm. The greater part of the philofophers who held the Plastic. exiftence of a plaftic nature, confidered it not as an agent in the ftrict fenfe of the word, but merely as an inftrument in the hand of the Deity; though even among them there were fome who held no fuperior power, and were of course as grofs atheists as Democritus himfelf Such was Strato of Lampfacus. This man was originally of the peripatetic fchool, over which he prefided many years, with no fmall degree of reputation for learning and eloquence. He was the first and chief affertor of what has been termed Hylozoic atheifm; a fyf tem which admits of no power fuperior to a certein natural or plaflic life, essential, ingenerable, and incorruptible, inherent in matter, but without fenfe and confcioufnefs. That fuch was his doctrine we learn from Cicero, who makes Velleius the Epicurean fay, "Nec audiendus Strato qui Phyficus appellatur, qui omnem vim divinam in Natura fitam effe cenfet, quæ caufas gignendi, augendi, minuendive habeat, fed careat omni fenfu t.' That De Natura Strato, in admitting this plaftic principle, differed wide- Derum, lib. ly from Democritus, is apparent from the following account of him by the fame author: " Strato Lampfacenus negat opera deorum fe uti ad fabricandum mundum, quæcunque fint docet omnia effe effecta natura, nec ut ille, qui afperis, et levibus, et hamatis uncinatifque corporibus concreta hæc effe dicat, interjecto inani; fomnia cenfet hæc effe Democriti, non docentis fed optantis §." i. cap. 13. Acad. eft. lib. IV. cap. 38. That the rough and fmooth, and hooked and crooked, atoms of Democritus, were indeed dreams and dotages, is a pofition which no man will controvert; but furely Strato was himself as great a dreamer when he made fenfation and intelligence refult from a certain plaftic or fpermatic life in matter, which is itself devoid of fenfe and confcioufnefs. It is, indeed, inconceivable, to ufe the emphatic language of Cudworth, "how any one in his fenfes fhould admit fuch a monftrous paradox as this, that every atom of duft has in itself as much wifdom as the greateft politician and moft profound philofopher, and yet is neither confcious nor intelligent!" It is to be obferved of Strato likewife, that though he attributed a certain kind of life to matter, he by no means allowed of one common life as ruling over the whole material univerfe. He fuppofed the feveral parts of matter. to have fo many feveral plaftic lives of their own, and feems to have attributed fomething to chance in the Gud. Int. production and prefervation of the mundane fyftem. Soft ed. Mofheim, In denying the existence of a God, perpetually di-lib.i. cap. 3recting his plaftic principle, and in fuppofing as many of thefe principles as there are atoms of matter, Strato deviated far from the doctrine of Ariftotle. The great founder of the peripatetic school, as well as his apoftatedifciple, taught that mundane things are not effected by fortuitous mechanism, but by fuch a nature as acts regularly and artificially for ends; yet he never confiders this nature as the highest principle, or fupreme Numen, but as fubordinate to a perfect mind or intellect; and he exprefsly affirms, that "mind, together with nature, formed or fashioned this universe." He evidently confiders mind as the principal and intelligent agent, and nature as the fubfervient and executive inftrument. deed, we are ftrongly inclined to adopt the opinion of the learned Mofheim, who thinks that by nature Ari, ftotle meant nothing more than that porns tuxion, or animal heat, to which he attributes immortality, and of De Gene which he exprefsly fays that all things are full. Beimal. lib. this iii. cap. 1 2 In ratione A PLA he fays, that "the nature of bodies fignifies the aggre Plaftic, [ 27 ] Plaftic. this as it may, he always joins God and nature together, and affirms that they do nothing in vain. The fame doctrine was taught before him by Plato, who affirms that "nature, together with reafon, and according to it, orders all things." It must not, however, be concealed, that Plato feems to have attributed intelligence to the principle by which he supposed the world to be animated; for Chalcidius, commenting on the Sect. 53. Timæus ‡, thus expreffes himself: "Hæc eft illa ratio. nabilis anima mundi, quæ gemina juxta meliorem naturam veneratione tutelam præbet inferioribus, divinis difpofitionibus obfequens, providentiam nativis impertiens, æternorum fimilitudine propter cognationem beata." De Dog- Apuleius, too, tells us ||," Illam cœleftem animam, fonmate Plato- tem animarum omnium, optimam virtutem effe genetricem, fubferviri etiam Fabricatori Deo, et præfto effe ad omnia inventa ejus." Plato pronunciat. mis. This doctrine of Plato has been adopted by many This writer is Mr Young, of whofe active fubflance, and The author, after a fhort introduction, enters upon his 66 any. Solidity (he fays) is the quality of body which prinfion, and which refifts other folids, occupying the place cipally requires our notice. It is that which fills extenwhich it occupies; thas making extenfion and figure real, and different from mere space and vacuity. If the fecondary qualities of bodies, or their powers, variously to affect our fenfes, depend on their primary qualities, it is chiefly on this of folidity; which is therefore the most important of the primary qualities, and that in which the effence of body is by fome conceived to confift. This idea of folidity has been judged to be incapable of any analyfis; but it appears evident to me (continues our author), that the idea of folidity may be refolved into within the extenfion of body. Hence it becomes unneanother idea, which is that of the power of refifting ceffary, and even inadmiffible, to fuppofe that folidity in That folidity in the body, and we know nothing of fofenfation of the body is at all a pattern or archetype of our fenfation"" lidity any where elfe, is no pattern of ours, is indeed most true, as we have shown at large in another place, (fee METAPHYSICS, n° 44 and 171): but to reconcile this with what our author afferts imme than colours and flavours are, and that it is equally with diately afterwards, that "folidity is no more in bodies our ingenuity is by no means equal. He affirms, indeed, them a fenfation and an idea," would be a task to which our ingenuity is by that folidity, as it is faid to be in bodies, is utterly ina fenfation in ourselves, but that in bodies nothing more comprehenfible; that we can perfectly comprehend it as is required than a power of active refiftance to make upon our fenfes thofe impreffions from which we infer the reality of primary and fecondary qualities. This power of we apprehend to be that which all other philofophers refiftance, whether it ought to be called active or paffive, have meant by the word folidity; and though Locke, who uses the words idet and notion indifcriminately, often talks of the idea of folidity, we believe our author to be the firft of human beings who has thought of treating folidity as a fenfation in the mind. Though it is wrong to innovate in language, when writing on fubjects which require much attention, we muft, however, acknowledge it to be unworthy of inper ufe of terms, fo long as the meaning of him who quirers after truth to dispute about the proper or improemploys them can be easily discovered. We fhall, there this power of refiftance is which is commonly known by fore, follow our author in his endeavours to afcertain what the name of folidity. All power he justly holds to be active; and having, by an argument (A) of which we do D2 not "(A) We can only conceive fold:ty as being a refiftance of the parts of any body, to a power which endea may be carried on ad infinitum, the only positive idea Plastię. which is fuggefted by atoms, or the parts of atoms, is the idea of a refifting power. That this power of refiftance, which conftitutes what is vulgarly called the folidity of bodies, may not be abfolutely impenetrable, he attempts to prove, by fhowing that refiftance does in fact take place in cafes where impenetrability, and even folidity, are not fuppofed by any man. Plastic. not perceive the force, attempted to prove that it is by an inward power, and not by its inertia, that one body prevents another from occupying the fame place with itLelf, he naturally enough infers matter to be effentially active. "But the activity of matter is to be confidered in a certain limited fenfe, and its inertnefs is to be regard ed in another limited fenfe; fo that thefe are compatible within their refpective limits. The activity of body may be confidered as belonging to the parts of a compound; its inertia as the inertia formed of thofe parts. The actions of the parts are everywhere opposed to each other, and equal; and hence refults the inactivity of the whole." SOLIDITY alone of the primary qualities being pofitive, and peculiar to bodies, and our author having refolved this into ACTION or POWER, it follows, by his analysis, that the ESSENCE OF BODY is reduced to power likewife. But, as he properly obferves, power is an idea of reflection, not acquired by the fenfes, but fuggefted by thought. Hence our knowledge of real exiftence in body inuft be fuch as is fuggefted to us by our thoughts exercised about our fenfations. "We are capable of acting and producing changes in appearances; and this faculty, which we experience to exift in our felves, we call power. We are confcious of the exertion of our own power; and therefore, when we fee ACTION OF CHANGE happen without any exertion of ours, we refer this to other powers without us, and neceffarily conclude the POWER to exift where the change begins or the action is exerted. This power, then, referred to bodies, muft exist in them, or it can exift no where." In two chapters, which might easily have been compreffed into one not fo long as the shorteft of them, our author analyzes atoms or the primary particles of matter, and ftrenuously opposes their impenetrability. He allows that there are atoms of matter not divifible by any known force; but as these, however small, muft ftill be conceived as having extenfion, each of them must be compofed of parts held together by the fame power which binds together many atoms in the fame body. This power, indeed, he acknowledges to operate much more forcibly when it cements the parts of a primary atom than when it makes many atoms cohere in one mafs; but ftill it operates in the fame manner: and as the ideal analyfis "Let us endeavour (lays he) to bring together two like poles of a magnet, and we shall experience a refistance to their approximation. Why, then, may not a piece of iron, which between our fingers refifts their coming together, refift by an efficacy perfectly fimilar, though more ftrongly exerted? If magnetifm were to act upon our bodies as upon iron, we should feel it; or were mag nets endowed with sensation, they would feel that which refifts their nearer approach. The refifting extenfion between the two magnets is permeable to all the rays of light, and reflecting none is therefore unfeen; but it is eafy to conceive that the fame power which refifts the approach of the iron might refift and reflect fome rays of light. We fhould then have a vifible object interpofed between the two magnets, as we have before fuppofed it might be a tangible one. It is likewise easy tə conceive that which is tangible and visible so applied to our organs of tafting, of fmelling, and of hearing, as to excite ideas of flavours, odours, and founds. Thus we see that an action, in which no fuppofition of foli. dity or impenetrability is involved, may be conceived to affume all the qualities of matter, by only fuppofing a fa miliar effect extended in its operation." This reafoning is exceedingly ingenious, though per haps not original; but what is of more importance, it does not approach so near to demonftration as the author feems to imagine. If magnets operate by means of a fluid iffuing from them (fee MAGNETISM, chap. 3.), thofe who hold the folidity or impenetrability of matter will maintain, that each atom of the magnetic fluid is folid and impenetrable. That we do not fee nor feel thefe atoms, will be confidered as no argument that they do not exift; for we do not fee, nor in a close room feel, the atoms of the furrounding atmosphere; which yet Mr Young will acknowledge to have a real exiftence, and to be capable of operating upon our fenfes of hear ing and fmelling. Let us, however, suppose, that by this reafoning Yours to feparate them, or to bring them nearer together. Now that which refifts any power, and prevents its effect, is alfo a power. By refiftance, I mean here an active refistance, fuch as an animal can employ against an animal. If a horfe pulls against a load, he draws it along; but if he draws against another horfe, he is put to a itand, and his endeavour is defeated. When any endeavour to change the fituation of the parts of any folid is in like manner prevented from taking effect, and the parts retain their fituation, the fituation has plainly been prefer ved by an active refiftance or power, equivalent to that which was fruitlessly exerted on them.” Such is our author's reasoning to prove that matter is effentially active, and that from this activity refults our notion of its folidity: but does he not here confound' folidity with hardnefs, and impenetrability with cohefion? Hecertainly does; for water is as folid, in the proper fenfe of the word, as adamant, and the particles of air as the particles of iron. The parts of water are, indeed, separated with ease, and those of adamant with difficulty; but it is not because the latter have more folidity than the former, but because the power of cohefion, whatever it may be, operates upon them with greater force. Solidity is an attribute of a whole; hardness and softness results from the cohetion of parts. We do not at all perceive the propriety of the fimile of the horfe pulling a load, and afterwards pulling against another harfe. Is it because both horfes are active that one of them cannot prevail againft the other, and because the load is inactive that either of them may drag along a mass of iron of half a tun weight? If fo, double or triple the mafs, and a very ftrange phenomenon will be the refult; for we fhall have an active whole compounded of two or three inactive parts, even though thofe parts fhould not be in contact! r TO ACT he allows to be an attribute, and juftly ob- atoms. "Whatever portion of the ACTIVE SUBSTANCE is Having thus proved the neceffity of these three re- 29 7 pro Such is the active fubftance of Mr Young, and fuch That he has his theory of the formation of matter. not with fervility copied from the ancients, every reader of his book, who is not an abfolute ftranger to Greek and Roman literature, will readily acknowledge; and yet if his theory be well founded, he has difcovered a middle fubftance between mind and matter, more properly plaftic than Ariftotle or Plato, Cudworth or Berkeley, ever conceived. But truth compels us to add, that to us his theory appears to labour under infuperable objec tions. That there may be in the universe a substance efa propofition which we are by no means inclined to confentially active, and at the fame time not intelligent, is animal life, lead us to fufpect that there is fuch a fubtrovert. Various phenomena, both in vegetable and ftance; but it does not follow that we are inclined to He conceives his proof, indeed, to be "in its adopt our author's doctrine refpecting the formation of matter. nature not at all imperfect, or to fall fhort of demonftration; and if any one refufe it, he thinks it will be: neceffary for him to fhow, either that the explanation will ferve equally well." offered is not fufficient, or that fome other explanation To fhow that the explanation offered is not fufficient,. will not, we apprehend, be a very arduous task; but we have no inclination to attempt ourselves another explater no other account can be given than that which renation, because we believe that of the formation of mat-folves it into the fiat of the Creator. That it cannot be: manner which our author has very clearly defcribed, formed by the motion of an immaterial substance in the feems to be a truth fo evident as not to admit of proof; for if motion be, as he defines it, a change of place,. every thing that is moved muft. have the quality of extenfion. But all the parts of this active fubftance which are given to form an atom, move round a centre, and are: exprefsly faid to occupy_fucceffively different places in: the orbit of rotation. Every one of these parts, there fore, is an extended being and fince, according to our author produce an object that is hideous and difguftfulto every Plaftic. man of taste. Figures like thefe offend by affording too exact an imitation of nature. In no one of the polite arts ought imitation ever to approach fo near the truth as to be taken for nature herself. Illufion must have its bounds; without which it becomes ridiculous. Plaftic. author, folidity is nothing but an active power of refift ance, and the parts of this active fubftance, in their rotation round their centre, ne upon and refit whatever interferes to oppofe their activity, it follows that each of thefe parts is likewife a folid being. But, in the opinion of Mr Young himself, and of all mankind, whatever is extended and folid is material. This theory, therefore, exhibits a procefs in which atoms are formed of a fubstance, which, though it is faid to be active, immaterial, and unfolid, appears, when narrowly infpected, to be nothing else than a collection of thofe very atoms of which the author pretends to explain the formation. Mr Young, who examines and very freely cenfures fome of the doctrines of Newton and others, is too much a man of science to be offended at us for ftating objections to a theory which is quite new, to a transformation which he himself acknowledges may to many 66 appear not only problematical and difficult to conceive, but wholly impoffible, and implying contradictions abfolutely and for ever irreconcileable." Whether this be a juft character of it our readers muft determine; but if we did not believe the author to be a man of ingenuity, we fhould not have introduced him or his work to their acquain 'tance. PLASTIC Art, the art of reprefenting all forts of figures by the means of moulds. This term is derived from the Greek word razsın, which fignifies the "art of forming, modelling, or cafting, in a mould." A mould in general is a body that is made hollow for that purpose. The artist makes ufe of them to form figures in bronze, lead, gold, filver, or any other metal or fufible fubftance. The mould is made of clay, ftucco, or other compofition, and is hollowed into the form of the figure that is to be produced; they then apply the jet, which is a fort of funnel, through which the metal is poured that is to form the figures, and that is called running the metal into the mould. It is in this manner, but with much practice and attention, that the artift forms, 1. Equeftrian and pedeftrian statues of every kind; 2. Groups; 3. Pedestals; 4. Bafs-reliefs; 5. Medallions; 6. Cannons, mortars, and other pieces of artillery; 7. Ornaments of architecture, as capitals, bafes, &c.; 8. Various forts of furniture, as luftres, branches, &c. in every kind of metal: and in the fame manner figures are caft in ftucco, plafter, or any other fufible matter. See PLASTER of Paris. Wax being a fubftance that is very easily put in fufion, plaftics make much ufe of it. There are impreffions which are highly pleafing in coloured wax, of medallions, baffo and alto relievos, and of detached figures; which, however, are fomewhat brittle. But this matter has been carried too far: they have not only formed moulds to reprefent the likeness and the buit of a living perfon, by applying the plafter to the face itself, and afterwards cafting melted wax into the mould; but they have alfo painted that waxen buft with the natural colours of the face, and have then applied glafs eyes and natural hair; to which they have joined a ftuffed body and limbs, with hands of wax; and have, laftly, dreffed their figure in a real habit; and by these means have produced an object the most shocking and deteftable that it is poffible to conceive. It is not a ftatue, a bust, a natural refemblance that they form; but a dead body, a lifeless countenance, a mere carcafe. The ftiff air, the inflexible mufcles, the haggard eyes of glafs, all contribute to There is another invention far more ingenious and pleafing, which is that wherein M. Lippart, antiquary and artist at Dresden, has fo much excelled. He has found the means of resembling, by indefatigable labour, great expence, and infinite tafte, that immenfe number of ftones, engraved and in camaieu, which are to be seen in the most celebrated cabinets. He has made choice of thofe that are the most beautiful; and, with a paste of his own invention, he takes from these ftones an impreffion that is furprifingly accurate, and which afterwards become as marble: thefe impreffions he calls pafti. He then gives them a proper colour, and inclofes each with a gold rim; and, by ranging them in a judicious order, forms of them an admirable fyftem. They are fixed on pafte boards, which form fo many drawers, and are then inclofed in cafes, which reprefent folio volumes, and have titles wrote on their backs; so that these fictitious books may conveniently occupy a place in a library. Nothing can be more ingenious than this invention; and, by means of it, perfons of moderate fortune are enabled to make a complete collection of all antiquity has left that is excellent of this kind; and they copies are very little inferior to the originals. There is also another method of taking the impreffions of camaieus, medals, and coins, which is as fol lows: They wash or properly clean the piece whofe impreffion is to be taken, and furround it with a border of wax. They then diffolve ifinglafs in water, and make a decoction of it, mixing with it fome vermilion, to give it an agreeable red colour. They pour this paste, when hot, on the ftone or medal, to the thickness of about the tenth part of an inch; they then leave it exposed to the fun, in a place free from duft. After a few days this pafte becomes hard, and offers to the eye the most admirable and faithful reprefentation of the medal that it is poffible to conceive: they are then carefully placed in drawers; and thoufands of thefe impreffions, which comprehend many ages, may be included in a small compafs. The proficients in plaftics have likewife invented the art of cafting in a mould papier maché or diffolved paper, and forming it into figures in imitation of fculpture, of ornaments and decorations for ceilings, furniture, &c. and which they afterwards paint or gild. There are, however, fome inconveniences attending this art; as, for example, the imperfections in the moulds, which render the contours of the figures inelegant, and give them a heavy air: these ornaments, moreover, are not fo durable as thofe of bronze or wood, feeing that in a few years they are preyed on by the worm. The figures that are given to porcelain, Delft ware, &c. belong alfo to plaftics; for they are formed by moulds, as well as by the art of the sculptor and turner;* and by all thefe arts united are made vafes of every kind, figures, groups, and other defigns, either for use or ornament. From this general article the reader is referred to FOUNDERY, CAST, GLAZING, PORCELAIN, P.PINRA Maché, POTTERY, DELFT Ware. PLA Κ |