Page:Cyclopaedia, Chambers - Volume 2.djvu/945

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irtaaive, and would lie eternally confin'd to its Beds of Earth without advancing up into Plants ; did not Water, or feme like Inttrument; fetch it forth, and carry it into them. . ,,.

This Fluid Is capacitated for the Ofhce here afiign d it, feveral ways : By the Figure of its Parts, which, as appears from many Experiments, is exactly and mathematically fpherical j theit Surfaces being perfectly polite, and without any the leaft Irregularities. It is evident, Corpufcles ot fuch a Figure are e'afily fufceptible of Motion, and far above any others whatever ; and confequently the moft capable of moving and conveying other Matter that is not fo ac- tive : then, the Intervals of Bodies of that Figure, are, with refpeft to their Bulk, of all orhers, the large!!, and jo the molt fitted to receive and entertain foreign Matter in them ; befides, as far as the Trials hitherto made inform us, the conltituent Corpufcles of Water, are each fingly con- fider'd, absolutely folid, and do not yield to the greatett ex- ternal Force ; This fecures their Figure againft any Altera- tion, and the Intervals of the Corpufcles muft be always alike. By the latter, it will be ever difpoled to receive Matter into it ; and by the former, when once received, to bear it along with it. Water is farther capacitated to be a Vehicle to this Matter, by the Tenuity and Fincnefs of the Corpufcles of which it confifts : We hatdly know any Fluid in all Nature, except Fire, whofe conttituent Parts are fo exceeding fubtile and fmall, as thofe of Water are : they will pafs Pores and Interlaces, rhat neither Air nor any other Fluid will. This enables them to enter the fineft Tubes and Veffels of Plants, and to introduce the terreftrial Mat- ter, conveying it to all Parts of them ; whilft each, by means of Organs it is endu'd with for the purpofe, intercepts, and affumes into it felf fuch Particles as are fuitable to its own Nature, letting the reft pafs on thro' the common Ducts. 8°. Water is not capable of performing this Office to 'Plants, unlefs affifted by a due quantity of Heat. This muft concur, or Vegetation will not fucceed. The Plants fet in the Glaffes in Ottobcr, and the following colder Months, had not near the Quantity of Water fent up into them, or fo great an additional Increafe, by much ; as thofe that were fet in Jane, July, and the hotter Months. It is plain, Water has no power of moving it felf, or riling to the vaft height it doth, in the more tall and lofty Plants ; fo far from it, that it doth not appear from any Difcovcry yet made, that even its own Fluidity confifts in the inteftine Motion of its Parts ; whatever the Cartefians think. In- deed, we need nothing more to folve all the Phaaiomena of Fluidity, than fuch a Figure and Difpofition of Parts, as Water has : Spherical Corpufcles muft ftand fo very tickliih upon each other, as to be fufceptible of every Impreffion; and tho not petpetually in Motion, muft be always ready and liable to be put into it, by any the flighted Force ima- ginable : 'Tls true, the Parts of Fire, or Heat, are r.ot ca- pable of moving themfelves, any more than thofe of Water ; but they are more fubtile, light, and active, than thofe are, and fo more eafily pur into Motion. See Fluidity.

That the Concourfe of Heat in this Work is really necef- fary, appears not only from the Experiments before us, but from all Nature ; from the Fields and Forefts, Gardens and Orchards : We fee in Autumn, as the Sun's Power is gra- dually lefs and lefs, fo its Effects on Plants is remitred, and Vegetation flackens by little and little. Its Failure is firft difcernable in Trees ; which being railed higheft above the Earth, requite a more intenfe heat, to elevate the Water charg'd with Nourifhment, to their Tops ; fo that for want of frefti Support and Nutriment, they ftied their Leaves, unlefs fecured by a very firm and hard Conftitution indeed, as our Evergreens are : Next, the Shrubs part with theirs ; and then the Herbs, and lower Tribes : the Heat being, at length, not fufficient to fupply even thefe, tho fo

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nay, there are fome Regions fo cold, that they raife no Ve- getables at all to a confiderable fize ; this we learn from Greenland, Iceland, and other Places of like cold Situation and Condition : In thefe there are no Trees, and the Shrubs are poor, little, and low. Again, in'the warmer Climates,_ and fuch as do furnilh Trees, and the large Vegetables, if there happen a Remiffion or Diminution ot the ufual Heat, their Productions are impeded in proportion : Our cold Sum- mers give us Proof enough of this ; for tho at fuch times the Heat we have, is fufficient to raife the Vegetative Mat- ter into the lower Plants, our Corns, Wheat, Barley, Peafe, and the like ; and we have plenty of Strawberries, Rasber- ries, Goofeberries, Currants, and the Fruits of fuch Vegeta- bles as are low and near the Earth ; and a moderate Store of Cherries, Mulberries, Plums, 0c. and fome others that grow ar fomewhat greater height ; yet our Apples, Pears, Walnuts, and the Productions of the taller Trees, have been fewer, and thofe not fo thoroughly ripen'd, and brought to that Perfection, as they are in more benign and warm Sea- sons : and indeed, in Trees of rhe fame Kind ; thofe rhat keep clofeft to the Earth, always produce the moft and beft Fruit : For which Reafon it is, that the Gardeners check and retain the Growth of their better Fruit- Trees, and pre- vent their running up to too great a height. As to our Grapes, Apricots, Peaches, Necfarins, and Figs, they being tranfplanted hither out of hotter Countries, it is the lefs won- der we have a Failure of them in cold Summers. Nor is it the Sun, or the ordinary Emiffion of the Subterranean Heat only, that promotes Vegetation, but any other indiffe- rently according to its Power and Degree ; as we find from our Stoves, Hot- Beds, &C. See Heat, Cold, Water, Earth, Soil, Tree, Dwarf, Pruning, igc.

VEGETATIVE, a Term applied to that Principle, or Part in Plants, by Virtue whereof they receive Nourifhment, and grow, or vegetate. See Vegetation.

The Philofophers fpeak of three Kinds of Souls, the Ve- getative, Senjltive, and Rational. See Soul.

The Vegetative Soul, is that Principle whereby Trees and Planrs live, grow, produce their Kind, iSc. See Plant.

This Vegetative Principle is differently feated in different Plants: An ingenious Author obferves, that, generally fpeaking, its Place is exaftly between the Trunk, and Root ; at leaft, this appears to be the Place in moft of the Semi- niferous Tribe; which, if cut down near that Place, rarely ilioor again.

In other Plants, as the Elm, and many edible Plants, it feems to refide wholly in the Roots ; which, if cut into e- ver fo many Parts, yet, thofe being planted in the Ground, foon grow. See Root, and Planting.

In others, as the Willow Kinds, it feems to be diffu- d all over, both Root, Trunk, and Branches ; infomuch t; at if cut into a thoufand Pieces, there is no deftroying 'em with- out fplitting 'em in the middle ; and fcarcely then. See Foecundity.

Lattly, In others, as the Cereus's, Ficus's, %$c. it is feated in the Body, Blanches, and Leaves ; any of which being put into the Ground, ftrike Root immediately, and grow.

The Office of this Vegetative Principle, is to concoft the indigefted Salts which afcend thro' the Roots ; and to afli- miiate 'em to the Nature of the Plant. See Vegetation.

VEHICLE, in its literal Senfe, fignifies fomewhar that carries, or bears a Thing along : Thus, in Anatomy, the Serum is faid to be the Vehicle that conveys the Globules of the Blood. (See Blood.) And in Pharmacy, any Liquid to dilute another with, or to adminifter it in, to a Patient, is called a Vehicle. Water is the Vehicle of the nutririous

Matter of Vegerables. See Vegetation.

VEIL, a piece of Stuff, ferving to hide, or prevent the Sight of any thing.

In this Senfe, we read of a

ge Veil, or Curtain, in the

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Dearths Earth, the Fund of their Nourifhment. As the Temple of Jerusalem, miraculouily rent at the faflion ot Heat returns the fucceeding Spring, they all recruit again, our Saviour. See Temple.

and are furnifh'd with frefti Supplies and Verdure : But firft, thofe which are loweft, and neareft the Earth, and that require a leffer degree of Heat to raife the Water with its carrhv Charge into them : then the Shrubs and higher Ve- getables, in their rums ; and lattly, rhe Trees. As the Heat increafes, it grows too powerful, and hurries rhe Mar- ter with too great Rapidity, thro' finer and more tender Plants : Thefe, therefore, go off, and decay ; and others that are more hardy and vigorous, and require a greater de- gree of heat, fucceed in their Order. By which Mechanifm, provident Nature furnilhes us with a very various and dif- fering Entertainment ; and what is beft fuited to each Sea- fon, all the Year round.

As the Heat of rhe feveral Seafons affords us a different Face of Things, fo the feveral diltant Climates fhew the different Scenes of Nature, and Productions of rhe Earth. The hotter Countries ordinarily yield rhe largeft and ralleft Trees, and thofe, too, in a much greater Variety than the colder; even thofe Plants common to both, attain to a much greater Bulk in the Southern, than the Northern Climes :

In the Roraifi Churches, in time of Lent, they have Veils, or large Curtains over the Altar, Crucifix, Images of the Saints, &c. . '

The Term Veil is alfo ufed for a large piece ot Crape, wore on rhe Head by the Nuns ; as the Badge of their Pro- feflion : Hence, to take the Veil, is to commence Religious.

The Novices wear white Veils ; and thofe who have made the Vows, black Veils. See,NovicE.

The Prelate before whom the Vows are made, bleffes the Veil, and gives it the Religious. See Religious, Be- nediction, &c.

VEIN, Vena, in Anatomy, a Name given to leveral Veffels, or Canals, which receive the Blood from the divers Parts of the Body, to which the Arteries have convey'd it from the Heart ; and carry it back to the Heart again. See Blood, ($c.

The Veins are only a Continuation of the extreme papil- lary Arteries, reflected back again towards the Heart. See Cafillary, and Artery.

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