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Show FI FI F I Pi ———$——__ of Heat; fo the Heat is infeparable from the whether the Sun fhine or not; either in the Fire. moft {corching Summer, or the fharpeft Win. The fecond Effect of Elementary Fire is ter, Fire may be collected byfeveral Methods, Dilatationin all folid Bodies, and Rarefaction as Attrition, or otherwife. Ina Word, there Mr. Grave(ande fays, That Quickfilver contains Fire, is evident hence, that if you fhake ic about in an exhaufted Glafs, it will appear all Juminous, Elementary Fire ofit {elf always lies conceal'd, of two that both thefe are infeparable from Heat: If Sticks will not render it fenfible. you heat an Iron Rod, it will increafe in all its The Cartefians, as Mariotie, Perrault, &¢ Dimenfions, and the more it is heated, the hold, That there isa large Stock of Fire. ina farther it will be increas’d; and being again perfect Vacuum, i: e. a Space out expos'd to the Cold, it will contraét, and fuc- the Air has been exhaufted, as of which all fuppofing an ceffively return through all Degrees ofits abfolute Vacuum impofli ble: Now the moft Dilatation, till it arrives at its firft Bulk, be- perfect Vacuumthat we can arrive at, is that ing never two Minutes fucceffively of the fame of Mr. Huysens’s Contriv ance, whichis as folMagnitude, lows: Heat a Quantityof the pureft Mercury The like may be obferv’d in Gold, the to the Heat of boiling Water, and pourit into heavieft of all Bodies, which takes up more a hot Tube of about forty Inches long ; and Space when it is fufed than it did before ; nay, whenthe Tube is fill’d, apply a Finger upon even Mercury, the heavieft of all Fluids, has the Orifice ofit, and thus invertit intoa Bafon been known to afcend to above thirty times full of Mercury: The Mercury will nowbe its Height, being plac’d over the Fire in a fufpended in the Tube to the whole Heicht: narrow ‘Tube. but then if you give it buta little Shake. it nay, it may be perfectly undifcoverable, where in all Fluids. Numerous Experiments make it evident, The Laws of this Expanfion are; 1ft, That the fame Degree of Fire rarefies Ua 1a a dla A elena is no Phyfical Point affignable without 1 , no Place in Nature where the Attrition will fink downto the Height of about twenty- nine Inches, and thus leave a perfect Vacuity Fluids fooner and in a greater Degree thanit of eleven Inches, does Solids. Without this, the Thermometer Yet here the Philofophers above-mention’d would be of no Ufe; fince if it were otherwife deny there is any Vacuum, and urge, that now the Cavity of the Tube would be dilated in fo much the more Fire is enter’d into the the fame Proportion as the Fluid is rarefied. Space as there was of other Matter: But this 2dly, By how much the Liquid is lighter. is contrary to Experience, at | the Fire by fo much the moreit is dilated by Fire: contain’d there is no hotter than the Mercury Thus dir, which is the lighteft of all Fluids. it felf; for if a Drop or two of Waterbe ina expands the moft; and Spirit of Wine the frofty Seafon {prinkled both upon the upper next after Air. Part of the Tube, fuppos’d to be full ofFire, : The third Effect of Fire on Bodies is Mo- and on the lower that is full of Mercury, they ‘ dies, 1meat ae arly ene move their er Parts. pore And a in effect, all the Motion in Nature arifes from Fire alone ; andif this were taken away, all things would become immoveable. All Oils yoy Wines, eel Spirits of Wine, getables, Animals, &c. become hard, rigid and inert upon the Abfence of only a certain Degree of Fire; and this Induration will be both the fooner and the more violent the lef; the Degree ofFireis. : . Hence if the Fire were abfolutely taken away, andthere were the greateft Degree of Cold, all Nature would grow into one concrete Body, folid as Gold, and hard as a Diamond; but upon the Application of Eire ® would recover its former Mobility, ° _And of confequence, every Diminution of Fire is attended with a proportionable Diminution of Motion, Pure Fire is found in two different Manners, cither as it exifts every where. Fadl is diffus d equally in all Places; ‘or as it exifts in nae in which it makes no great x he fhould exift in the fame Quantity ae that ee ml feem a ftrange Paradox, and Jote at it does oea . gs demonftrable from J This ElementaryFire is prefent every where, in all Bodies, all Space, a that in equal Quantities nd at all Times, and 2; for Jet a Perf on go where he will, to the ’ Yop of the high eft Mountains, or defcend in to the loweft Cavern, will in each Place freeze alike; fo that thereis no more pure Fire in a perfeét Vacuumthan in anyother Place, But whereas it has been faid, that Fire is found in all Bodies: 'To provethis, fet Gold againft the Vacuum before mention’d, and this Gold, tho’ the moft ponderous ofaj] Bodies, will not contain more Fire than Huygens’s Va- cuum, as appears from the Thermometer. _ But the Fire in Gold, when readyto fule, is pure Fire ; for a Mafs of this be ing once heated red hot, will retain this Fire perfectly for three Days: Nay, the Prince of Miraudola and others have kept Gold ignited for two Months without any Diminution of Weight. Mr, Gravefande, Phyf. Element. fays, That Bodies of any Kind being violently moyd againft one another, will grow hot byfuch Friction, and this to a confiderable Degree, which fhews that all Bodies have Fire in them : For Fire maybe put in Motion, and feparated tom a Body byfuch rubbing, but can never be generated that Way. A Mr. Boyle, Mech. Prod. of Heat, fays, That whereas Quickfilver is allow’d to be the coldett of all Fluids, infomuch that many denythat it will produce any Heat by its immediate Aion onanyother Body, and particularly onGold; but feveral Trials have affured me, that a par- ticular Mercury maybyPreparation be inabled fuddenly to infinuate it felf into the’Body of Gold, whether calcin’d or crude, and become manifeftly hot with it in lefs than two orthree Minutes gthiy, by Heat; and shtly, by Burning. That there is a good Quantity of Fire even in the coldeft Places, and in the coldeft Bodies, is confirm’d by the following Experiment: Ifyou take two large Iron Planes, and rub them briskly together in Iceland, which is only twelve Degrees fhort of the North-Pole, in the moft frofty Seafon, and at Midnight, Sun’s Heat, infomuch that Water will freeze almoft inftantaneoufly ; and hence is the Ufe of Ice-houfes, But a little lower, about forty or fifty Feec deep, it begins to grow warmer, fo that no Ice can bear it; and then the deeper they go ftill the greater the Heat till at length it en dangers the Stoppage of Refpiration, and puts out their Candles: If they venture yet farther with a lighted Candle, the Place fhall be immediately found full of Flame, as once happen’d in the Coal Pits in Scot/and, where an hardy Digger defcending to an unufual Depth with a Light in his Hand, the Fumes, which were there found very copious, caught Fire thereby, and burnt the whole Mountain down. Therefore it feems as if Nature had Jodg’d another Sun in the Center of the Earth, to concribute on its Part to the giving of Motion to Bodies, and for the promoting of Generation, they will grow warm, glow, fhine, and heat Nutrition, Vegetation, Germination, &c. it is in the greateft Quantity, as is evident in the Zorrid Zone, where the Snow never melts, notwithftanding the great Abundance of Fire. This Fire, in it felf thus perfectly latent, may difcover itfelf to be prefent by five EF fects; 1ft, by rarefying Bodies, and particularly Air; 2dly, by Light ; 3dly, by Colour ; to fuchaPitch, as not only to rarefy the Spirit inthe Thermometer, but even to ignite, and at laft to fufe, Now the Fire here found is either created de novo, or it was there before; but no body will affert its Creation, and accordingly, unlefs it be furnifh’d with a proper Fuel, it will be foon diffipated again, but not annihilated, and of confequence it pre-exifted, and it appears to be true Fire byits rarefying the Spirit in the Thermometer. From this, and many other Experiments, it is evident, that Fire is always found inall Parts of Space, and inall Bodies equally {pread on the utmoft Top ofthe higheft Mountain, as in the fubjeét Valley, or in the deepeft Cavern under-ground, and in every Climate, and at every Seafon. The equable Diftribution of Fire in all Places being provd, it fhould thence follow, that there is the fame Degree thereof every where ; which would really be fo, were it not that Fire happens by one Meansorother to be more collected in one Place than another. But, notwithftanding, the equable Difference, ec. of Fire through all the Mundane Space, does not hinder, but that, to our Senfes, it appears very unequal in different Places: And hence we have two vulgarly of Animals, Vegetables and Foffils. As to the Origin of this fubterraneous Sun, fome doubt whether it were form’d there in the Beginning,like the Sun in the Firmament, or gradually producd by a fecondary Collection of vague Fire into this Place. What makes in Favour of the former Opinion, are Vulcano’s or burning Mountains, which feem to have exifted from the firft Ages; for the Flames of Mount tna are mention’d as of great Antiquity; and there are likewife fuch Mountains found in the coldeft Regions, wiz. Nova Zembla, and IceJand, as well as the hotteft, as Borneo, &c. It cannot be reafonably pretended, fays Mr. Boyle, that the fubterraneous Heat proceeds from the Rays of the Sun, fince they heat not the Earth above fix or feven-Feet deep, even in the Southern Countries ; and if the lower Part ofthe Earth were of its own Nature cold, and receiv’d the Heat it affords only from the Sun and Stars, the deeper Men defcend therein, the lef; Degree of Heat and Steams they would meet with. The Sun contributes muchin bringing Fire to light, by Means ofhis rapid Motion round his Axis, whereby the fiery Particles, every where diffus’d, are directed and determin’d in parallel Lines towards certain Places whereits Effects become apparent. And from thence it is that the Fire is perceiv’d by us when the Sun is above ; but that when he difappears, his Impulfe or Preffion but one excepted, who held the Sun to be being then taken away, the Fire continues difcold. pers‘d at large through the Etherial Space. There is not in effect lefs Fire in our HeAs to the fecond, the Central Fire; it is on manifeft that there isan ample Proporti of mifphere in the Night-time than there is in the Day-time, onlyit wants the proper Deteround Fire under-gr ; and even, that Fire apPears much more abundant there than on the minationto caufe it to be perceiv’d. The Effeéts of Elemental Fire may be-inSurface ; fo that at leaft, a /ubterraneous Fire mutt be granted. creas'd divers Ways, viz. firft, by Attrition, Thus they who dig Mines, Wells, €?c. con- ora {wift rubbing or agitating one Body againft ftantly obferve, that while they are but a another. ‘This is very manifeft in Solids: litle below the Surface, they find it a litele The Attrition of a Flint againft a Steel proool, and as they proceed lower it proves much duces Sparks of Fire: And likewife in Fluids, colder, as being then beyond the Reach ofthe the violent Agitation of Cream by churning Ooo will reputed Sources or Funds ofFire, viz. in the Sun, and the Centre of the Earth. As for the firft, we have the concurrent Opinions of the Philofophers of all Ages, |