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Show LI LI there are no Intervals deftitute of Matter: Whence it follows, that as no Portion of Matter is fo fmall, but that Body wherein it is con- tain’d, may be wholly divided into Parts equally fmall, there can be no Reafonfor the Defcent of thefe, which will not equally hold for the Defcent of that. Hence it may be concluded, that thofe Bodies which do not equally gravitate under the fame Dimenfions, do not contain the fame equal Portions of Matter; and therefore when we fee that a Cube of Gold fubfides in Water at the fame time that an equal Bulk of Cork fwits upon it, it is evident that the Gold muft have a greater Number of equal Parts of Matter under the fame Bulk than the Cork; or the Cork muft have a greater Number of Vacuities than the Gold; and that there are alfo in the Water a greater Number ofVacuities than in the Gold. Hence we have a clear Idea both of De 2, the latter cannot be accounted anything pofitive, but a mere Negation or Abfence of Body, which determines that Body to be lighter than another which contains mere Matter. LI Body in right Lines; and with an incredible Velocity. Forit has been demonttrated by Mr. Romer, from the Obfervation on the Satellites of Jupiter, that the Progrefs of Light from the Sun to our rth is not above ten Minutes, andtherefore, fince the Earthis at leaft 10,000 of its own Diameters diftant from the Sun, Light muft run 10,000 of thofe Diameters in a Minute, which is above 100,000 Miles in a Second. Andif a Bullet moving with the fame Cele. rity, with which it leaves the Muzzle of 2 Cannon, requires twenty-five Years to pafs from the Earth to the Sun, as Mr. Huygens has computed, then the Velocity of L will be to that of a Cannon-Ball, as 25 Yearsis to 10 Minutes, which is above 10,000 to 13 fo that the Particles of Light do move above a Million of times fwifter than a Cannon Bullet ; from which Rapidity of Motion very flrange Effects may be produc’d : But Sir I/aac Newton has fhewn, paft Contradiction, that the Light of the Sunis near feven Minutes inits Paflage to the Earth, which is the Space of 50,000,000 5 a Velocity 10,100,000times greater than that wherewith a Ball flies out of the Mouth of a times it fignifies that Senfation which is occafion’d in the Mindby the Viewof luminous Bodies. 2. For thofe Properties in thofe Bodies, Cannon. Sir Yaac Newton alfo obferves, Tha and Light act mutually on one | on Light in emitting, reflexin andinflecting it; and Lig dodtes Dy heat ing them, and putting their Parts into a vi- whereby they are fitted to excite thofe Senfa- brating Motion, wherein Heat principally con- tions in us. fifts: LIGHT is us’d in various Senfes: 1. Some- 3. A certain Aétion of the luminous Body on the by the aét on Light, For he obferves, that all fix’d Bodies, when heated beyonda certain Degree, do Medium, between that and the Eye, Means of which the one is fuppos’d to the other; and this is call’d fecondary or deriv’d Light, in Diftinétion to that emit Light, andfhine ; which Shining, 3c. ap= pears to be owing to the vibrating Motion of the Parts; and all Bodies abounding in earthy andfulphureous Particles, if theybe fufficiently ofluminous Bodies, which is call’d primary or agitated, emit Light, which Way foever the Agitation be effected. innate Light. As tothe Phenomenon of Light, Philofophers have explain’d it feveral Ways: otle, by fuppofing fome Bodies to be tranfparent, as Air, Water, Ice, &c. The Cartefians have confiderably refin’d upon this Motion of Light, and own that Light, as it exifts in the lumi- nous Body, is nothing elfe but a Power or Faculty ofexciting in us a very clear and vivid Senfation: And Father Malbranch explains the Nature of Light by a fuppos’d Analogy between it and Sound ; the latter of which is allow’d to be produc’d bythe Shaking or Vibration of the infenfible Parts of the fonorous reateft Difcoveries into this wonxenon have been made by Sir the Primary Light confifts a certain Motion ofthe Particles of Body, whereby they do not propel ious Matter fuppos’d to be lodg’din the h en Pores of tranfparent Bodies, but throwoff from the luminous Body certai n very {mall Particles, which are emitted every Way with great Force, And the Jecondary or di d Light, not in a Conatus, but in a real Motion ofthefe Parles rece recedi veryy Way ucies Wav fro ding ever fi m the lumii nous bility, and Colour; Degrees of Refrangibility, which infer as many 3. Licusrtcum ; Gracum, Apii folio. T. Cor. Gteek Lovage, with a Parfley Leaf. 5. The Rays of Light do not a& one on anThe firfk of thefe Plants is often us’d in other in paffing through the fame Medium. Medicine, and was formerly reckon’d amongft 6. The Rays of Light do not fuffer any the Kitchen Herbs, but is now aloft intirely Alteration of their Qualities from Refraction, caft out of the Kitchen-garden, and only culnor from the adjacent quiefcent Medium. tivated for Phyfical Ufes: This Plant may be n. There can be no homogenial Colours eafily propagated by fowing the Seeds, foon produc’d out of Light by Refraction, which after they areripe, in a moift Spot of Ground ; are not commix’d init before; fince Refraction and when the Plants come up the Spring folchanges not the Qualities of the Rays, but only lowing, they fhould be tranfplanted out to the feparates thofe that have divers Qualities by Diftance of eighteen Inches of two Feet afunmeansof their different Refrangibility. der, in a moift Soil ; where, if they are kept § The Sun’s Light isan Aggregate of ho- clear from Weeds, they will thrive exceedmogeneal Colours; whence homogeneal Co- ingly. and the fecond Summer will produce lours may be call’d Primitive or Original. Seeds: But the Herb may be frequently cut Hence proceeds the whole Theory of Co- for Ufe, their Roots abiding feveral Years, do lours in Plants and Flowers. fhoot again continually after being cut ; fo that Thofe Parts, v. g. which are the moft re- a few Plants will be fufficient for the Ufe of a frangible, conftitute Violet Colour, the dim- Family. meft and moft languid of all Colours. The fecond and third Sorts are only pre= And, on the contrary, thofe Particles that fery’d in Collections of Plants for Variety, but are the leaft refrangible, conftitute a Ray ofa are not in any Ufe at prefent. Thefe may be red Colour, which is the brighteft and moft propagatedin the fame Manneras the former. vivid of al] Colours: The other Particles being diftinguith’d into little Rays, according LIGUSTRUM; the Privet. to their refpective Magnitudes and Degrees of Refrangibilicry, excite intermediate Vibrations, other ; the Flower confifts of one Leaf, is tubulous, and divided at the Top into five Segments 5 of Colours. Perhaps thefe Obfervations on Light may to fome Perfons feem foreign to the fubject the Ovary in the Center of the Flower-cup be- Matter of this Book, yet, if throughly underftood, might probably be found very ufeful. That learned and curious Inquirer into the Bufinefs of Vegetation, the Reverend Mr. Stephen Hules in his Treatife on that Head, does upon the Query put bySir c Newton: (“* Are {s Bodies and Light convertible into oé@ and thofe Rays which geneal: Again, the Colours exhibited by homogeneal Light, he calls homogeneal Colours’ requird Rays endu’d with all the ind egret a thei m. ay not Be wes yvecerve ivity from the Particles of er their Compofition ? The di two, whence they may be well defin’d homo- bility. a ae 2. That Rays, which differ in Refrang whenparted from one another, do proporti ably differ in the Colours which they exhibit. 3. That there are as many fimple and homogeneal Colours, as there are Degrees of Refrangbility; for to every Degree of Refra belongs a different Colour. — ae 4. Whitenefs, in all refpects, like that | \ ufua the all of and Light, the Sun’s immediate Objeéts of our Senfes, cannot be compoun’@ offimple Colours, without an ind , ) of them ; for to fuch a Compofition ¢ another ? * agree in Refrangibility, agree alfo in the other 1. That the Sun’s Ligh? confifts of Rays differing by indefinite Degrees of R¢ The Charaéfers are ; The Leaves grow by Pairs oppofite to each andfo occafion the Senfitions of the intermediate Colours. See Sir J/aac Newton's Doctrine babel and thofe produc’d by heterogeneal hy g terogeneal Colours. From which Definitions he advances feveral Propofitions : I fimple Colours, The famegreat Author obferves, That there are but three Affections of bt wherein the Rays differ, viz. Refrangibility L comes a globular foft Fruit, full of Fuice, in which ave lodg’d four Seeds. The Species are ; 1. Licusrrum; vulgare. Park. Theat. The common Privet. 2. Licustrum; foliis majoribus Magis acuminatis toto anno folia retinens. Pluk. Alm The Ever-green Privet. 3. Licustrum; foliis 2 luteo variegatis. H.R. Par, The yellow blotch’d Privet. 4. Licustxum; foliis argentatis. Breyn. Prod. ‘The Silver-ftrip’d Privet. ght, and of Light The firft of thefe Plants is very common in is very conformable to the Courfe ch fcemsdelighted with Tran/>) Add this Query ; “* 4nd may if y entring the expanded Flowers, contribute the Prin moft Parts of England, and is feldom culti= LIGUSTICUM; [takes it Name of Licuria, becaufe t this Plant, in old time, grewin greateft re near a River ofGenoa, call’d Liguria.) «OY. vated in Gardens, unlefs for Variety: It commonly grows about eight or ten Feet high, in Form of a Shrub, but may, by Art, be train’d up to a much greater Height, and maybe in- termix’d amongft other Trees of low Growth in Wilderneffes, The fecond Sort will grow much larger than the firft, and is equally hardy: The Leaves ofthis commonly remain upon the Treeuntil the Spring before they decay, unlefs. in very hard Winters ; for which Reafon, it is more efteem’d than the common Sort. Thefe Plants are eafily propagated by lay2 Leaves, whith ex t Role ; each of thefe F y two obloug, gibbofe, on one Side have a leafy Border. ing down their tender Shoots in Autumn, whichin one Year’s time will be rooted enough to tranfplant ; when they may be remoy’d to the Places where they are defign’d to remain, or planted in a Nurfery for two or three he Species are ; pofes defign’d. 1. Licusticum; vulgare, foliis Apii. F. B. Common I ovage. 2. Lisusticum ; Scoticum, Apii folio, Tourn. Scotch Lovage, with a Parfley Leaf. Years; where they maybe train’d for the PurFormerly thefe Plants were greatly in Ufe for Hedges, but fince fo many others of greater Beauty have beenintroduc’d, which are thuch preferable to thefe for fuch Purpofes, they gs A have |