4 



F 



matter -, but this is contrar>' to experience -, at leaft, the 

 fire contained there is no hotter than the mercury itfelfi 

 for it a drop or two of water be in a frofty feafon 

 forinkled both upon the upper part of the tube, fup- 

 pofcd to be full of fire, and on the lower that is full of 

 rnercurv, they will in each place freeze alike •, fo that 

 there is no more pure fire in a perfed vacuum, than 

 in any other place. 



But whereas it has been faid, that fire is found in all 

 bodies, to prove this, fet gold againft the vacuum be- 

 fore-mentioned, and this gold, though the moft pon- 

 derous of all bodies, will not contain more iire tlian 

 Huysens's vacuum, as appears from the thermo- 

 meter. 

 But the fire in gold, when ready to fufe, is pure 



fire ; for a mafs of this being once heated red hot, 

 willVetain this fire perfectly for three days -, nay, the 

 prince of Mirandola and others, have kept gold ig- 

 nited for tv/o months, without any diminution of 



weight. 



Mr. Gravefande, Phyf Element, fays. That bodies 



of any kind, being violently moved againft one ano- 

 ther, will grow hot by fuch fridtion -, and this to a 

 confiderable degree, which fhews that all bodies have 

 fire in them ; for fire may be put in motion, and fe- 

 paratcd from a body by fuch rubbing, but can never 

 be generated that way. 



Mr. Boyle, Mech. Prod, of Heat, fays. That although 

 quickfilver is allowed to be the coldeft of all fluids/ 

 infomuch that many deny, that it will produce any 

 heat by its immediate aftion on any other body, and 

 particularly on gold •, yet feveral trials have afifured 

 him, that a particular mercury may by preparation be 

 enabled fuddenly to infinuate itfelf into the body of 

 gold, whether calcined or crude, and become mani- 

 feftly hot with it in lefs than two or three minutes. 



- Mr. Gravefande fays. That quickfilver contains fire, 



; is evident hence, that if you fhake it about in an 

 exhaufled glafs, it will appear all luminous, 

 Elementary fire of itfelf always lies concealed ; nay, 

 it may be perfeftly undifcoverable, where it is m the 

 gfeateft quantity ; as is evident in the torrid zone, 

 where the fnow never melts, notwithftanding the great 

 abundance of fire. 



■ This fire, in itfelf thus p^rfeflly latent, may difco- 

 * ver itfelf to be prefent by five cfFefls ; ift, by rare- 

 fying bodies, and particularly air ; 2dly, by light ; 

 3dly, by colour; 4thly, by heat; and 5thly, by 

 burning. >..- - ' ; : 



^ That there is a good quantity of fire even in the 

 coldeft places, and in the coldeft bodies, is confirmed 

 by the following experiment : if you take two large 

 iron plates, and rub them brifkly together in Iceland, 

 which is only twelve degrees fhort of the nqrth pole, 



t in the moft frofty feafon^ and at midnight, they will 



grow warm, glow, ftiine, and heat to fuch a pitch as 



;^not only to rarefy the fpirit in the thermometer, but 



' -even to ignite, arid at laft to fufe'; 



* 



^^'^ V 



■Vt-.r-^. 



■"XT 1 /• ^ -_ _ _ ^ - . _. -_ 



^^ow the fire here found is either created de iiovo, or 



"'^ -it was there before, but nobody will aflert its crea- 



/ tibn; and accordingly, unlefs it be furnifbed with a 



■ proper Fuel, it will be foon difllpated again, but not 



annihilated; and of confequence it pre^exiftcd, and it 



appears to be true fire by its rarefying the fpirit in 



the thermometer. 



- ■ » ' 1 



-■* ^ - 



' From this, and many other experiments, it is evi- 

 dent, that fire is always fovmd in all parts of fpace, 

 and in all bodies equally fpread on the utmoft top of 

 the higheft mountain, as in the fubjedt valley, or in 



^ the deepeft cavern under ground, and in every cli- 

 mate, and at every feafon. . 





jf fire in all places being 



proved, it ftiould thence follow, that there is the fame 

 degree thereof every where ; which would really be 

 io, were it not that fire happens by qne means or other 

 to be more collefted in one place than another. 

 But, notwithftanding the equable difi'erence, &c. of 

 fire thrciugh all the mundane fpace does not hinder, 

 ' bur that, to our fenfes, it appears very unequal in dif- 

 ferent places ; and hence we have two vulgarly re- ) 



puted fources or funds of fire, viz. in. die fun, a:id 

 the center of liie earth. 



As for the firft, we have tlxe concurrent opinions of 

 the philofophers of all ages, but one excepted, who 

 held ti^e fun to be cold. 



As to the fecond, the central fire, it is manifcft that 

 there is an ample proportion of fire under <-rround ; 

 and even, that fire appears much more abundant 

 there than on the fuiface ; lb that at leaft, a fubtcr- 

 rancous fire muft be granted. 



Thus they who dig mines, wells, &c. conftantlv ob- 

 ferve, that while they are but a little below the fur- 

 face, they find it a little cool ; and as they prcc.eed 

 lower, it proves much colder, as being beyond the 

 reach of the fun's heat, infomuch that water will 

 freeze ahr.oft inftantaneoufly, and hence is the ufe of 

 houfes. 



But a little lower, about forty or fifty feet deep^ it 

 begins to grow warmer, fo that no ice can bear it ; 

 and then the deeper they go, ftill the greater heat ; 

 till at length it endangers the ftoppage of refpiration, 

 and puts out their candles. If they venture yet farther 

 with a lighted candle, the place ftiall be immediately 

 found full of flame, as once happened in the coal-pits 

 in Scotland, where a hardy digger, defcending \o an 

 unufual depth, with a fight in his handy the fumes, 

 which were there found very copious, caught fire 

 thereby, and burnt the whole mountain down. 

 Therefore it feei:^.s as if nature had lodged another 

 fun in the center of the ^arth, to contribute on its 

 part to the giving motipri to bQ4ies, ^nd for the pro- 

 moting of generation, putrition, vegetation, germi- 

 nation, &c. of animals, vegetables, and folTils. 

 As to the origin of this fubteirraneous fiin, {omp 

 doubt whether it were formed there in the beginning, 

 like the fun in the firmament, or gradually produced 

 by a fecondary collection of vague fire into this place. 

 What make^ in favour of the former opinion^ are 

 volcanos or burning mountains, which feem to have 

 exifted from the firft ages ; for the flame? of rriouQt 

 ^tna are mentioned as of great antiquity, and there 

 Jire likewife fuch mountains found in the coldeft re- 

 gions, viz. Nova ZembU aud Iceland, as wtJl as the 



hptteft, as Borneo, Sec- 

 It cannot be reafi?nably pretended, fays Mr- Boyle, 

 that the fubterraneous heat proceeds from the i:ays of 



the fun, fince they heat not the earth, above fij; or fe- 

 ven feet deep, even in the fouthern countries > and if 



the lower part of the «rth were of it^ own mature 



cold, and received the heat it ^ffprds^ only ff pm the 



, fun ^nd ftars> the deeper men defcend therein, th?lefs 



degree of hgataoditeam^ they wpuld mee| with*' . 

 ,. The fun contributes ixi^ch^ in bringing fire to light, 

 t. by reafon of his rapid HiPtfon round his axis j whereby 

 ..£the fieiy particles, every where diffufed, are directed _ 



tnd determined in parallel lines tpw^rd certain places 

 where its eSefts become apparent, 

 LAnd from thence it is, that the f\rej§ P?r£€jye.d by 

 us when the fun is above-, but that when he cjifap- 

 pears, his impulfe or preflTion being then teiken away, 

 .>:the fire continues difperfed at large through the ethe- 

 :.realipace. :.vr; '^Mv^r ^ .- . 



^>: There is not, in effeft, lefs fire in our hemifphere in 

 x:the*night time, than there is in the day time i only it 

 wants the proper determination to gavfc it tg b? per- 

 ceived. . - r 



•i2 



*--..': 



h 1 



*_-_>-- -^ <'■■■ 





■ 





-*T J 



«; 1 - 



■ - - 



^\^ 



j_ h 



The efFe6ts of elemental fire may be increafed divers 

 ways, vi?, firft, by attrition, or a fwift rubbing or 

 agitating one body againft another. This is very ma- 

 nifeft in folids. The attrition of a flint againft a fteel 



produces fparks of fire -, and likewife in fluids, the 

 violent agitation of cream, by churning, will prpducc 

 a fenfible warmth, and feparate it into butt?r i and 

 this effea: is rendered ftill more difcernible by a ther- 

 mometer. ' 



And the heat of animal bodies is owing to the agita- 

 tion and attrition of the parts of thefe juices againft 



each other, and the fides of the veflTels. 

 The fecond manner of Jncreafing the tffcQ: of ele- 

 mentary fire is, by throwing a quantity of mpift or 



:■ green 



-J 





4 , ^ 



r - 



^ -' 





