229. And, upon comparing this with the like Cafes, we have fome- The Morin of times entertain'd a ftrange Sufpicion; viz. whether the Stars of a clear by from the filed Sky be feen by us at the precife Time they really exift, or rather, fomewhat later; and, whether there be not, with regard to the Sight of the Heavens, a true and apparent Time, as well as a true Place, and apparent Place; which is obferved by Aftronomers in the Parallaxes. For it feems incredible, that the Rays of the celeftial Bodies fhould inftantly travel fuch an immenfe Diftance to the Sight; and not rather take up fome confiderable Time in the Journey. ". 230. But this Sufpicion, as to any great Interval betwixt the real and Is extremely apparent Time, afterwards vanifh'd; upon confidering that infinite Lofswift. and Diminution of Quantity, as to Sight, between the real Body of a Star, and the apparent Object; which Difference is caufed by the Diftance; and, at the fame time, confidering to what a Diftance Objects that are barely white may, of a fudden, be feen here below; amounting to fixty Miles at the leaft: for there is no queftion, but that the Light of the celeftial Bodies has not only the vivid Strength of Whitenefs; but also vaftly exceeds the Light of Flame, as we find Flame here, in Power and Strength of Radiancy. Nay, that immenfe Velocity wherewith grofs Matter moves, in the diurnal Rotation, renders this wonderfully swift Motion of the Rays of Light, from the Fixed Stars, more probable. But what has the greatest Weight with me, is this; that if there fhould here be any confiderable Space of Time between Reality and Sight; or the Existence of the Object, and its being feen; it must then happen, that the Sight would be frequently intercepted and confounded by Clouds, arifing in the mean time; or by the like Difturbances in the Medium. And thus much for the fimple Menfuration of Time. Actions, to be 231. The Measure of Motions and Actions is not, however, to be The Meafures fought only fimply; but much rather comparatively: this being a of Motions and Thing of excellent Ufe; and having regard to very many Particulars. found compaWe find, that the Flash of a great Gun is feen before the Sound is ratively. heard; altho' it is certain that the Bullet must strike the Air, before Motions that the Flame, which was behind it, could get out; and that this must differ compahappen from a greater Velocity in the Motion of Light, than in the ratively. Motion of Sound. We find also, that visible Objects are fooner received than let go by the Sight; whence it is that the Strings of a mufical Inftrument ftruck with the Finger, appear double, or treble, in the Vibration; viz. because a new Object is received before the other is difcharged and, for the fame Reafon, Rings twirling upon an Axis seem Spheres; and a lighted Flambeau, carried haftily by Night, appears tail'd, like a Comet. See this Time computed by M. Huygens de la Lumiere, p. 8 and 9. See alfo Sir Ifaac Newton upon the Subject; and compare them both with the Papers of M. Maraldi in the French Memoirs, Ann. 1707 w See, again, Mr. Whifton's Effay upon the Longitude. X X X 2 232. And Whence Gali 232. And, from this Foundation of the Inequality of Motion in point læo accounted of Velocity, Galileo imagin'd the Caufe of the Flux and Reflux of the for the Tides. Sea to be from the Earth's revolving with a greater Velocity than the The Use of the comparative Measure of Motions, exemplified in Powder Mines. This the Foun Waters: whence the Waters gathering into a Heap upwards, afterwards funk down by degrees; as we fee in a Veffel of Water brifkly revolved. But this Solution he invented barely upon Suppofition, and not upon Proof, of the Earth's Motion; and alfo without being well informed of the fexhorary Motion of the Sea. 233. But we have an eminent Example of the comparative Measure of Motion, and at the fame time of its remarkable Ufe, in the Business of Powder-Mines; wherein vaft Maffes of Earth, Piles of Buildings, &c. are overturn'd, and tofs'd into the Air with a small Quantity of Gunpowder. The Caufe whereof is, doubtlefs, this; that the Motion of Dilatation in the Powder, which is the impelling Force, is many Degrees fwifter than the Motion of Gravity, which makes the Resistance; fo that the prevailing Motion is perform'd, before the oppofite Motion begins : whilft, at first, there was a kind of Neutrality, or want of Refiftance. And hence, in all Projectiles, it is not fo much the ftrong, as the sharp and quick Stroke, or Percuffion, that carries the Body fartheft. Nor was it poffible that a fmall Quantity of Spirit in Animals, especially in those fo bulky as the Elephant, or the Whale, fhould move, and manage fo great a Mafs of Matter; but for the Velocity of the Motion of the Spirit; and the Inability of the corporeal Mafs to refift. 234. And this is one of the principal Foundations of the Magical Indation of Ma- ftances, which we fhall foon confider; wherein a finall Quantity of Matter gical Infan- overpowers and fubdues a much greater: that is, where there may be a Pre-occupation, or Anticipation of Motions, by the Velocity of one, before another is ready". ces. The Cafe to be 235. Laftly, this Bufinefs of Anticipation and Subfequence, fhould regarded in all be obferved in all natural Actions. Thus in the Infufion of Rhubarb, natural Acti- the purgative Virtue is drawn out firft; and the aftringent Virtue afterwards a. And fomething of the like kind we have found upon infusing Violets in Vinegar; where the fweet and delicate Odour of the Flowers is first received; and afterwards the more earthy Part; which confounds the Odour therefore, if Violets be infused for a whole Day, their Smell is obtain'd much fainter, than if they were infufed only for a Quarter of an Hour, and then taken out. And becaufe Violets contain but little odoriferous, Spirit, if frefh ones be infufed in the fame Liquor, every Quarter of an Hour, for fix Times; the Tincture, or Infufion, will become fo rich in the Space of an Hour and an half, as to continue, for a whole * See Vol. III. p. 624. y See below, Aph. 51. 2 2 This deferves to be carefully confider'd and remember'd; for many extraordinary Operations, and Cafes of Practice, depend upon it. a See the Sylva Sylvarum under the Article Infufion. See the Place laft cited. a whole Year, of an exceeding grateful Odour, not inferior to the Flowers themselves. But it must be obferved, that the Odour does not come to collect its full Strength, till a Month after the Infufion is made. And the Bufinefs of Diftillation affords numerous remarkable Examples to the fame Purpose. APHORISM XLVII. 236. In the twenty-third Place, among Prerogative Inftances, come In- (23.) Inftances Stances of Quantity; which we alfo call the Dofes of Nature: borrowing of Quantity, or Dofes of the Expreffion from Medicine. These are fuch Inftances as measure Vir- Nature. tues by the Quantities of Bodies; and indicate what the Quantity of a Body contributes to the Quantity of Virtue. 337. And, firft, there are certain Virtues fubfifting only in a Cofmical Exemplified in Quantity; that is, fuch a Quantity as has a Confent with the Configuration various Partiand Structure of the Univerfe. Thus the whole Body of the Earth, unmoved fuppofe in its Whole, does not fall downwards, tho' its Parts do the Waters ebb and flow in the Sea, but not in Rivers; unlefs where they communicate with the Sea and almost all particular Virtues operate in proportion, as the Body is bigger or lefs. Large Collections of Water do not eafily corrupt; as fmall ones do. New Wines and Drinks ripen quicker, or become fooner potable, when contained in Imall Veffels, than when in large ones. If a Plant be added to a large Proportion of Liquor, it makes an Infufion rather than a Tincture; but if to a lefs, it makes a Tincture rather than an Infufion. So, with regard to the human Body, bathing is one Thing, but fprinkling another. And thus the fineft Dews never fall in the Air, but are diffipated and incorporated with it. And we fee in breathing upon polifh'd Gems, that the fmall Quantity of Moisture thus left upon their Surface, is presently licked up by the Air; as a light Cloud, or Mift, is diffipated by the Wind. Again, a Piece of a Loadftone will not attract fo much Iron as the whole Loadstone would do. 238. There are alfo Virtues, wherein Smallnefs of Quantity has the Smallness of greatest Effect; as a fharp Point penetrates easier than a blunt one; Quantity has and as the angular Point of a Diamond cuts Glafs: with other Examples Sometimes the greatest Effect. of the like kind. 239. But we are not here to dwell upon Indefinites; but fhould enquire The Measures into the Proportions of the Quantity of a Body, with regard to the of the Virtues in each Body, Measure of its Virtue: for one might eafily imagine, that the Propor- to be particu tions of Quantity correfponded to the Proportions of Virtue; as that a larly fought. leaden Bullet of two Ounces fhould fall twice as fwift as another of one Ounce; which is abfolutely falfe. Nor do the fame, but very different, Proportions, obtain in all kinds of Virtues and, therefore, thefe Mea See above, Aph. 44. fures fures must be derived from Experiments, and Things themselves; and not from Probabilities, or Conjectures. The Dofes of 240. Laftly; in every natural Enquiry, the Quantity of the Body reNature to be quired to produce any Effect must be fet down; as the Dofe: and the Jubjoin'd in e- Cautions, with regard to Quantity, either in Excess or Defect, contivery Enquiry nually interfpers'd. APHORISM XLVIII. (24.) Inftances 241. In the twenty-fourth Place come Inftances of Reluctance; which we of Reluctance. alfo call by the Name of Prevailing Inftances; that is, fuch as fhew the Predominancy, or Subjection of Virtues to one anothe; or which of them is the ftronger, and prevails; and which the weaker, and fubmits: for the Motions and Struggles of Bodies are no lefs compounded, recompounded, and complicate, than Bodies themselves. We will, therefore, firft lay down the principal Species of Motions, or active Virtues; that their Comparison, in Point of Strength, may be the clearer; and thence the Inftances of Reluctance and Prevalence, be the better known and defigned. Belong to all the Species of Motion. Motions divi ded and diftin- ance. Яion. 242. The first Motion may be the Motion of Refiftance in Matter, or the Motion that refides in all the Parts thereof, and will not fuffer it to be any way annihilated; fo that no Force of Fire, no Weight, or Depreffion, no Violence, no length of Time, or Continuance of Duration, can ever poffibly reduce any the leaft Particle of Matter to nothing; but it it will ftill continue fomething; pofsess a certain Space; and to whatever Neceffity it be reduced, free itself, either by changing its Form or Place; or, if it cannot do that, it will continue as it was; fo that the Time fhall never come, when it is nothing, or has no Existence. And of this Motion we need produce no Examples, because it is univerfal, or exifts in all Bodies ". (2.) The Mo243. Let the fecond Motion be that we term Motion of Connection; whereby tion of Conne- Bodies fuffer not themselves to be divided, or feparated from others, on account of the mutual Contact and Connection they affect which is a Motion call'd by the Schools, the Motion preventive of Vacuity; as when Water is forced upwards by Suction, or by the Pump; or when the Flesh is raised by Cupping-Glaffes; or, as when Water runs thro' a Siphon; with numerous other Examples of the fame kind . (3.) The Motion of Liberty. 244. Let the third Motion be what we call Motion of Liberty, or Freeing Motion; whereby Bodies endeavour to eafe and free themselves from any preternatural Preffure or Tenfion; or reftore themselves to the Dimenfions agreeable to their own Natures. And of this Motion alfo the Examples are numerous. Thus Water endeavours to free itself from Pref 3 See the Author's History of Condensation and Rarifaction, Vol. III. fure • Let it be confidered whether all these Motions are justly explained by the Weight, Spring, or Preffure of the Air. fure in the Action of Sailing, and Rowing; the Air, in the Action of Flying, and in the Undulations of the Winds; the Springs in Watches; comprefs'd Air in Pot-Guns, which forces out the Pellet, &c. 245. And, for this Motion of Liberty in the Cafe of Tenfion, we fee, Its Phænothe Air frees itfelf therefrom, when it remains after Suction in Glafs- mena in TenEggs; we fee it alfo in Strings, Leather, Cloth, &c. which restoreon. themselves after Tenfion; unless where they remained fo long ftretch'd, as to have their Motion of Liberty fubdued. This Motion is unfcientifically called, by the Schools, the Motion of the Elementary Forms: for it does not only belong to Air, Water, and Flame; but to all the Diverfities of confiftent Bodies; as Wood, Iron, Lead, Cloth, Skins, &c. each Body having its own Measure of Extent or Dimenfion, from whence it is with difficulty ftretched to any confiderable Distance . 246. But as this Motion of Liberty is, of all others, the most obvious ; This Motion and alfo extremely general; it requires to be well and clearly diftin- to be well di guifhed: for fome very inadvertently confound it with the Motion of Re-ftinguished. fiftance, and the Motion of Connection. Thus when, by this Motion, Matter frees itself from Preffure, they confound it with the Motion of Refiftance; and when Matter frees itself from Tenfion, they confound it with the Motion of Connection; as if compreffed Bodies yielded or dilated themfelves only to prevent a Penetration of Dimenfions; and as if, when ftretched, they reftored, or contracted themselves, to prevent a Vacuum: whereas, if comprefs'd Air were to become as denfe as Water; or Wood as dense as Stone; there would be no danger of a Penetration of Dimenfions; even tho' thefe Bodies could be much farther compreffed than they any way admit of. So likewife, if Water were to be dilated to the fame Degree of Rarifaction with Air; or Stone to the fame Degree of Rarifaction with Wood; there is no Neceffity that a Vacuum should enfue; even tho' thefe Bodies could be extended much farther than their Natures any way allow". And therefore, the Cafe is not brought to a Penetration of Dimenfions, and Vacuity, except in the utmoft Limits of Condensation and Rarifaction: whereas thefe Motions ftop far fhort of thofe Limits; as being no more than Appetites which Bodies have of continuing themfelves in their own Confiftencies, or Dimenfions; and not fuddenly departing from them, unless altered by gentle Means, and by Confent. 247. But it is much more neceffary, as being a Thing of great Confe- Violent Mcquence, to obferve that violent Motion, as 'tis called, is no other than tion, the Mothis very Motion of Liberty, tending from Compreffion to Relaxation. tion of Liberty. For in all fimple Protrufion, or Flight through the Air, there is no Tendency to Motion, or Change of Place, before the Parts of the Body fuffer See above, Aph. 45. §. 220. preter See the Hifiory of Condenfation and Rarifattion, paflim; and the Article Motion, in the Sylva Sylvarum. See the Author's Hiftory of Cendenfation and Rarifaction, Vol. III. |