petites of a private Good do not generally prevail against the Appetites of a more publick Good, unlefs in fmall Quantities. And it were to be wifhed this alfo obtained in Civil Affairs 2. APHORISM XLIX. 308. Among Prerogative Inftances, we affign the twenty-fifth Place to (25) Intima Intimating Inftances; that is, fuch as hint, or point out, the Advantages ting Instances. or Conveniencies of Mankind: for bare Power and Knowledge only enlarge, but do not enrich human Nature; and therefore fuch Things as principally appertain to the Ufes of Life, are to be felected, or cull'd out from the general Mafs of Things. The more proper Place for speaking of thefe, will be when we treat of Reducing Knowledge to PraEtice. But through the whole Bufinefs of Interpretation, we conftantly, in every particular Enquiry, or upon every Subject, allot a Place for the Table of human Ufes; or the Table of Defiderata, Wishes, or Optatives a for it is a part of Knowledge to enquire, and even to wifh difcreetly. APHORISM L. 309. In the twenty-fixth Place, among Prerogative Inftances, come So- (26) Sovereign vereign, or General Inftances; that is, fuch as regard a Variety of Parti-Inftances. culars, and occur frequently: whence they greatly fave Trouble, and prevent the Search after new Demonftrations. But for the Inftruments themselves, and the particular Managements, the more proper Place to treat of them is, when we come to the Ways of Practice, and the Method of Experimenting for the Things hitherto known and used, in the Exercife of all particular Arts, muft be defcribed. But at prefent we will fubjoin a few Generals, with regard thereto; in the way of exemplifying thefe Sovereign Instances. e : Means of Practice. 310. Man, therefore, (befides the Bufinefs of fimply putting Bodies The fever together, and taking them afunder) operates upon natural Bodies feven Ways, or principal Ways; viz. (1.) by excluding fuch Things as might hinder or difturb the Procefs; (2.) by compreffing, extending, agitating, and the like; (3.) by Heat or Cold; (4.) by continuing the Matters in a convenient Place; (5.) by the moderating and governing of Motion; (6.) by particular Confents; (7.) by a feafonable and due Change, Alteration, or Series and Succeffion, of all the preceding Ways, or at least some of them. 311. With a Here is an Opening in that Kind of Perfian Magic, which the Author has profecuted farther on another Occafion. See Vol II. p 5. Let the feveral Kinds of Motion, above laid down, be compared with thofe of Sir Isaac Newton, and the modern Mathematical Writers. b See Vol. III. p. 17, 18, 19, &c. and the Sylva Sylvarum, paffim. ་ A Part not gone upon in the No um Organum. See above, Aph. 21. See the Clofe of the History of Winds, Vol. III. p. 497. and Condensation and Rarifaction, P. 571. See the Sylva Sylvarum throughout. See alfo the de Augment. Scientiarum, Sect. 12. The Inftru Covers. 311. With regard to the first Means of Practice; viz. by excluding ments and Con- fuch Things as might hinder or difturb the Procefs; the common Air, trivances re- which is every where at hand, infinuating itself, and the Rays of the Cequired in the first way; viz. leftial Bodies, caufe great Disturbance; and therefore fuch Things as Containing exclude them, may defervedly be accounted Sovereign. And to this beVeffels, and long the Matter and Strength, or Thickness, of the Veffels, wherein the Subject, or Bodies prepared for the Operation, are included; as alfo the exact Methods of clofing up thefe Veffels, with proper and trong Materials, or with Philofophical Luting, as the Chemifts call it. So likewife the clofing of Veffels, by means of Liquors applied on the outside, is a very useful Thing; as when they pour Oil upon Wine, or other vegetable Juices for the Oil floating on the top, like a Stopple, excellently preserves them from the Injuries of the Air. Nor are Powders unfit for this Purpofe; which tho' they contain a Mixture of Air, yet expel and prevent the Force of the external Air; as we fee in the Preferving of Grapes, and other Fruits, by Sand or Flower. So again, Wax, Honey, Pitch, and the like tenacious Bodies, are properly used with a View to clofe Veffels perfectly, and exclude the external Air, or Atmosphere. And we have fometimes buried Veffels and other Bodies in Quickfilver; the denfeft Fluid that can be employ'd for this Purpose. Caves, Pits, and Wells. The Diving- 312. Pits, Caves, and fubterraneous Receptacles, are likewife of great Ufe, to exclude the Sun; and the open Air, which preys upon Things. And these kinds of Caves are used, in the Northern Part of Germany, for Granaries. And to this Head belongs also the suffering of Bodies to lie at the bottom of Water. Thus I remember to have heard, that certain Bottles of Wine, let down to cool in a Well, being by a cafual Neglect left there and forgotten, for many Years, but at length drawn up again; the Wine was found to be grown, not vapid or flat, but much more generous and noble. But if it fhould be required to fink Bodies to the bottom of a River, or the Sea, without their touching the Water, or without being included in stopp'd Veffels, and yet be surrounded by Air; the Diving-bell, which is a Veffel fometimes employ'd for working upon Wrecks, or Ships under Water, may here prove of good Service. 313. This Veffel is made of Metal, hollow like a Cask; and being let down with its Bottom parallel to the Surface of the Water, it carries along with it all the Air it contains, to the bottom of the Sea"; and having three Feet to stand upon, fomewhat fhort of the Height of a Man, the Diver, when he wants to breathe, conveys his Head into the Cavity of the Veffel; where being refresh'd with Air, he afterwards continues his Work. And we have heard, that a Boat, or fmall Ship, was lately contrived, wherein f See Vol. I. p. 291. and Vol. III. p. 168, 169, &c. h See Dr. Halley's Account of the Diving-Bell, in the Philofophical Transactions, N•349. See alfo Vol. III. p. 566. wherein Men may row under Water, for fome Distance. However this be, under fuch a Veffel as we just now described, Bodies may be easily fufpended in Air, at the bottom of the Sea. tion. 314. There is also another Ufe of carefully including, and fhutting up, A new Use of Bodies in Veffels; viz. not only to keep out the external Air, but also close Operato keep in the Spirit of the Body, operated upon internally; for 'tis neceffary the Operator upon natural Bodies fhould be certain of his Quantities; or that nothing fhould expire or go off: for 'tis then that deep or great Alterations are made in Bodies, when, as Nature prohibits Annihilation, Art alfo prevents Lofs, or the Escape of any Part of the Subject. to it removed. 315. But a falfe Notion has here prevailed, which, if it were true, the An Objection Preservation of the entire Quantity of a Body, without Diminution, might be in a manner defpaired of. The Notion is this, that the Spirits of Bodies, and Air highly rarified by Heat, can be contained by no Veffels; but conftantly efcapes through their Pores. Men have been perfuaded to this Opinion, by thofe common Experiments; (1.) of inverting a Glafs, with a piece of lighted Paper, or Candle in it, into Water, whence the Water rifes upwards; and, (2.) of Cupping-Glaffes, which being heated with Flame, attract the Flefh. For Men have imagined in both Cafes, that the Air is attenuated, difcharged, and leffened in Quantity; whence the Water, or Flesh, fucceeds by the Motion of Connection". 316. But this is erroneous; for the Air is not here leffened in Quantity, but contracted in Space: nor does the Water rife before the Flame is extinguifhed; or the Air grown cold; infomuch that Phyficians, to make the Cupping-Glaffes draw the better, clap Sponges upon them, dipt in cold Water. Therefore Men need not be fo apprehenfive, that Air, or Spirits, fhould easily escape this Way: for tho' it be true, that the most folid Bodies have their Pores; yet Air or Spirit, will not eafily be fubtilized to fuch a Degree: as neither will Water pass thro' a very fmall Crack'. 317. As to the fecond Means of Practice; viz. by compreffing, ex- The Second tending, agitating, &c. 'tis principally to be obferved, that Compreffions Means of Praand fuch kinds of Violence, are of very great Force in local Motions, ice; viz. and the like; as in Machines and Projectiles; even fo as to deftroy organical Bodies, and their Virtues or Powers, which plainly consist in An Invention of this Kind is ufually attributed to Cornelius Drebbel, who is faid to have had a volatile Liquor for restoring the Air to its pristine Temper, after having been spoiled by Refpiration. 'Tis farther faid, that this Effect was produced barely by unftopping the Glafs, wherein the Liquor was contained. But of this Matter there feems to be nothing known with Certainty; or at best, not with the requifite Particularity. See above, §. 244. i The later manner of explaining this Phænomenon by the Rarifaction of the internal Air, and the Preffure of the external, will not here alter the Cafe; because the Air, upon this Suppofition, does not pafs thro' the Glafs. * See Vol. III. p. 614. 1 See more to this Purpose in Vol. III. p. 512. 613. VOL. II. Aaaa Motion: Violence. Whether Bo Force. An Experi Motion for as all Life, all Flame and Ignition, are deftroy'd by Compreffion; fo is every Machine fpoiled, and its Parts confounded, or deftroy'd, by the fame. They are alfo of Force to deftroy the Virtues confifting in Arrangement, or Position, and a fomewhat groffer Diffimilarity of Parts; as in Colours: for the Colour of a Flower, when whole, differs from its Colour, when bruifed; and fo the Colour of Amber when whole, differs from the Colour of Amber, when bruised. So again, with regard to Taftes; the Taste of an unripe Fruit is not the fame as when ripe, or after having been fqueezed and prefs'd; but manifeftly fweeter. These Violences, however, have no great Power over the more noble Transformations, and Alterations of fimilar Bodies; because Bodies, by their means do not acquire any new, permanent, and quiefcent State; but one that is tranfitory, and always endeavouring to restore and free itself. 318. But it might be proper to make fome careful Experiments to dies may be fhew, whether the Condenfation of a fimilar Body, as Water, Oil, &c. permanently or a Rarifaction violently introduced, may become conftant and fixed; condensed, or fo as to change, as it were, the Nature of the Subject and it fhould rarified by first be tried by bare Continuance, and afterwards by Helps, and Confents. This would be easier to do in the Experiment formerly mentioned for attempting the Condensation of Water, included in a Lead Veffel, and wrought by the Hammer, and the Prefs'; in which Cafe, the metalline Globe, when beat flat, fhould be left in that State, for fome Days before the Water was taken out; in order to fee whether it would immediately fill the fame Dimenfions it had before the Operation for if it did not, either immediately, or foon after, the Condenfation might seem to have been permanent; or otherwife, if the Water restored itself, the Compreffion would appear to have been only tranfitory. ment recom mended for condenfing Water. Another for 319. And fomething of the fame kind might be tried, as to the Exrarifying Air. tenfion and Rarifaction of the Air, in Glafs-Eggs, after the manner formerly mentioned 1: when, the Air being ftrongly extracted by Suction out of the Glaffes, and the Orifices fuddenly clofed, and well fecured; the Glaffes are to remain thus for fome Days; and afterwards to be opened, to fee whether the external Air would be attracted with a hiffing Noife in at the Orifices of the Glaffes; or, if being opened under Water, the fame Quantity of Water would be drawn in, as if they had been directly plunged into Water at firft, after the Air was fucked out. Such Condenfations and Rarifactions probable. 320. It is probable, (or at least deferves to be proved) that fuch Condenfations and Rarifactions may be made; becaufe Continuance of Time has the like Effect in Bodies a little more Diffimilar: thus, for Example, See an Experiment of this Kind performed upon Air, in Mr. Hauksbee's Phyfico-Mechani sal Experiments, p. 162---166. P See above, Aph. 45. §. 222. • See above, Aph. 45. §. 220. Example, a Stick being bent by Compreffion, for fome time, does not come ftrait again. And this cannot be attributed to any Lofs in the Quantity of the Wood, by the Continuance; because the fame thing happens alfo in a Plate of Iron, which is not exhalable. But tho' the Experiment fhould not fucceed by bare Continuance, ftill the Business is not to be deferted; but other Affiftances ufed": for 'tis no finall Acquifition, if fixed and conftant Natures may be given to Bodies by Violence; for thus Air might be converted into Water, by Condensation; and many Things of the like Kind be performable: for Man has a greater Command over violent Motions than he has over the reft. 321. The third Means of Practice regards that grand Engine, or In- The third ftrument, both of Nature and Art; viz. Heat and Cold. And here the Means of human Power feems perfectly Lame on one Side; for we have the Heat Practice. of Fire infinitely stronger, or more intenfe, than that of the Sun, as it naturally comes to us; or than the Heat of Animals: but Cold is wanting; unless so far as it may be procured by the Severity of Winter; by Caverns; or, by the Application of Snow and Ice: which, in the way of Comparison, may about equal the Degree of Heat, afforded by the The increasing Noon-day Sun, in fome Parts of the torrid Zone; increas'd by the Re- of Cold reverberation of Mountains and Walls: for fuch a Degree of Heat and commended. Cold, may, for a small time, be endured by Animals: but this is nothing to the Heat of a Melting-Furnace, or to a Degree of Cold, that anfwers to fuch a Degree of Heat. And therefore all Things, with us, tend but to Rarifaction, Deficcation, and Confumption; and fcarce any to Condensation, and Inteneration, or Supplenefs, unless by Mixture, and, as it were, by fpurious Means. Wherefore Inftances of Cold are with great Diligence to be fought after; fuch as may perhaps be found by expofing Bodies, at great Heights, in sharp Frosts; laying them in subterraneal Caves; furrounding them with Snow and Ice, in deep Places, or Refervatories made for the Purpofe; by letting Bodies down into Wells; burying them in Quickfilver, and Metals; plunging them in the Waters which petrify Wood"; burying them in the Ground, (as they relate of the Matter for making Porcellane) and the like. So likewife, the Condensations naturally made by Cold are to be fought, that their Causes being difcovered, fuch Condensations may be transferred into Arts. Such natural Condenfations we fee in the fweating of Marble and Stone; in the Dew condensed on the infide of Glass Windows, after a frofty Night; in the Such as large and strong Condensing Veffels, and Syringes, for compreffing and confining the Air. • The Experiments of this Kind feem to have been no way duly profecuted. The Succefs which Mr. Hauksbee met with, in a flight Attempt to deftroy the Spring of common Air, might very well encourage the Ufe of greater Violence, ftronger Veffels, and a greater Length of Time, for the Purpose. See his Phyfico-Mechanical Experiments, p. 162, &c. See the Sylva Sylvarum, under the Article Cold. "For producing the greatest Degrees of artificial Cold, by freezing Mixtures, fee Mr. Boyle's Hiftory of Cold; and the Chapter of Fire, in Dr. Boerhaave's Chemistry. |