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Eulers_Letters_on_Different_Subjects_in_Natural

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Google-scanned copy of a nineteenth-century book of Leonhard Euler's popular letters on natural philosophy written for a German princess. It is the American edition edited by John Griscom from David Brewster's version, with preface, a life of Euler and a contents list of the letters. Subjects include light, gravitation, magnetism and other physics. The text layer is noisy OCR, so details are approximate.

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Youcansearchthroughthefulltextofthisbookontheweb athttp://books.google.com/ 1 ,| = t J && “Phys LISSree(SoER) UNbIEY, = SON a Bt Elise 5OMSaavis ieAd\\e, <u {\a ( THEGIFT OF ic Gah ) an ibiwc Sey 3 on| Phys21.3See&fe) msbet ARNON sesoda | \ Nahe le a A ys i ele See 28 A SO Pa . ee — / : ® Lorharel LETTERS OF, EULER NATURAL PHILOSOPHY. . AOERMAN PRINCESS. SYDAVID BREWSTER LLD, BY JOHN ORISCOM, LD. Vou. 1. “NEW-YORK: 1837. “Phys 294.25 1674, Bef.t. 30.Myelvashunad Lxkere,Mr,Laruefernben15184) (Get.IL) ead,omfgActofCongoheor108,DyHaarenDownes, taecuesfefeSoulesDtofNewFa . _ | EDITORS PREFACE ‘TaxworknowpresentedforthefrsttimetotheAmerican pubiciatheproduction ofoneofthe‘mostlearned:andhighly-gitedmenwhosenames ‘adorntheannalsofsoundphilosophy,andwhosea laboursgainedforhimareputationinferioronlyto hatofNowton.Theywillbereadwithgreatad-‘vaniagebytheyoungstudent,onaccountoftheremarkable cleamesswithwhichthosubjectsarotreated,thecopiousness ofthestyle,anditsadapta-tiontothepurposeofeasyandfamilarinstruction,‘Theauthor,inadditiontohiaprofoundknowledge,Ihadtheadvantageofbeing,bothbyprofesionandbytaste,0teacherofyouth;andthevolumesbeforeusbearevidenceofthetactwhichanexpe‘encedintructeracquiresindiscovering thepoints‘whichstandmostinnoedofvariedandreiterated‘explanation. ‘Thetheorieswhichtheauthorendeavoursofan byelaboratereasoningtosupportae,itintre,inAa ‘TaxworknowpresentedforthefirsttimetotheAmerican publicistheproduction ofoneofthe‘mostlearnedendhighly-giftedmenwhosenames ‘adorntheannalsofsoundphilosophy, andwhoselaboursgainedforbimareputationinferioronlytothatofNewton.‘Theywillbereadwithgroatad-vantagebytheyoungstodent,onaocountoftheremarkable clearnesswithwhichthesubjectsaretreated,thecopiousnese ofthestyle,anditsadapta.tiontotheparposeofeasyandfamiliarinstruction.‘Theauthor,inadditiontohisprofoundknowledge,badtheadvantageofbeing,bothbyprofession andbytasto, teachorofyouth;endthevolumesbeforetusbearevidenceofthetactwhichanexperienced standmostinneedofvariedandreiterutsd expla-sation. ‘TheseLetters,therefore,designedastheywere|forthebenefitoflady,willpredisposetheingem-‘vousmindtotheloveofscientifictruth.Nori ‘theevidenceofpietyhebesbroughtintocennexion‘withsomeofthehighestcoatemplatioasofphiloso» phyoneoftheleastinteresting featuresofthesesagresablevolumes. AsanicanEptron, CONTENTS THE rineT VOLUME ©TirasPOFMapniodsorBitenin2oD. otOfMagneorEeenin=TB HESoestlndiaViney222 HStorrtinTie 22# NOGemansmacaomnePf rnsWySoreerendavemert ¢gXReekctovusPaciyofwae22 HeGromit corote or BeSPE ntnie28 AESRemar agde SV,TASERlcdtyetaGl3Boisedadothe’PyrometertelThe av.Obiefiabelinonten ed© arnkahtienecient” XVILOfgh,ndtheBystemsofDencanresend7 XVI,DIRwennteSyneag SERianwriteerent otter 2 Ie 6 conta, ccd cuheDateofheHearty™ eeeseeasXXILELAnoniNatsofLionsti, thastress OpenBosXXLHowOpeveRatnebecaevie, Newron'sTyotatelheHaseenoBayepope98 KAW.BalloHeian”AEOors XV,AltEspinoteSamarnie‘GpecueBoleionalbecomevale=108 XAvLgonatameSages 18 SVEGaheatn®SatinettClaropages BeteACOMP oy XxvunNesteCoospanielas2H ELIEPapeHeaneobne “Xxx.offieFaneofHascLighoh ‘uenparentMeio,atoeesac118 Zaxmelange SrCases==It ERIEOfayetengronscnantainsi, cay,offatsJogatalaoS aoepacerZANEOF.aidepa iailuanMine"RagenofRav,fom xxvRienSRaysgncateaeee SECinta.OFBingmeele XLOfVitandihSrcothPye388 SikGiguerea Feumascere ee, XLMLFortesintone AsomsiogDigcreesilPyererCnnOnectnanw IY,Pet!UsesBots X2y,ofSavy,alicegent Papago, XLVLContation.OfSpcinGviy:"Ses STEVESeta rteoeape et | cowrmers. 7 ~ EVEmagnal tetheMars | PathanfendetaOnt ux,TeeBoostsondhenoPOeasnaeanseTog PigerainCoutiesnfBlanaerMeese SeoheEa: oy uowigvuewes: 222 1B1bStayUaeOmitbyeLn:OStaton OfteitalAlinotianeBegeesASMEay*mgUnivereal:Gravitation.‘TheAimeLL.Power6wilhbeifawatewoBipTiemmeSeedomined 2BVIEHestteHearetyBato.“Matiof SeamysLamaCaer UxspelteUnies DLRS HtHorasSiecle 23S URESatiTrqaiiieteWemainooFantSthaeTemo {xn pefnPittHar LXIII.DifferentOpinionsofPhilosophers respecting sv,nie atata .AttractivePoweroftheMoon’-218 LAY. Themurbugercminnel” A.B HW,Remessufccue>le EBM:TOSSiscadeNpetngUneCratos2 xix.NeZawshiHatesBete”OfBtnieMehtyeotpnofBlyx LEX.tapeeeeTOmBS EEREGPaeCBeeadae:xxu.oft,sctaaundettNios30d RUPietLaeawattsootbePoetllcac. taza.ofterenaBonoeen, SEEKY,ChangesctichmaythepoeinGoSete 8 *Comranrs. LETSramofbeMonatWor=BS ritStemeesMaen ire”.2 ESNaeSeeseofat‘xxix.offGusionivthrveny eerSpecs paar AntaroeytieSci, Lxxx,oftbMtotSite7a BESiCaer acta natTRL Brsminulceof beSpeenofpre-eimesnaes nxxxry,ae mawks oe UY:SPSbathaeRtn. LxXKYLThamenetcme,eee AARNEMesoSSey"oft LXXXVI.OfEventsnatura,supematoral,andmoral”201 ‘LXXXLX. OftheQuestionrespecting the’bestWorld"rentaodWetEdae 20:oseion’ircOpole SevealSawaPan ouhedyelelg renteDeansoachs ou.Rincon ipetngbaNutrofSpies30k 2SBateau Ss asSc Denkeey OW cane neAteuues TehraneeeteeGSao HOV.ofttoreteBalaeS OVLCiooteBsnwatwopr areyeBeneOFetsStltetas, Sg pomneinPastiesVentealaseYoaes 0x.DESL iocnddicede ect” OFa ar 0ofethanofNaNena toooneaoat GLOfLanguage; itsNature,Advantages, and(Teese inci,aia comrnars. ® =Phewshiainao cx.oFTEPecosof nietamedatBieataetaitn covederpekine 27 cou.ofSygatetethraiePosteatsPeptoena0 crv.DetameyaSreutepeiedares Tsa VtBidetWigresaksofSylogiene-384 iiGusrcheantHatocteesctoa cormuppWesintSytem‘constructedof|‘oomsodSyliee=363 ax.oftefagsofBemtioncathSxl38 EEBeSenetfeinotErna Gxtofecentyden ba)2IT EEEGopCoasts eftheRiaesceof GeprentofteRaiteeeo (oxi,TiaPaDertationoa,”Uocesnd Rearaiectaets tiedoxtv,ofht"CtnnyiDotaeS: oxy,TaeFotiHonesBint onceoraanGames Sia cee ee PREFACE TrhasloogbeenareproachagainstEnglishlite-‘ature,thatthecomposition ofelementary andpopular‘workshasbeenleftalmostexclusively inthehandsofinferiorwriters,whopossessonlyageneraland ssupericialknowledgeofthesubjectsofwhichthey treat.‘Theinfluenceofthispracticeuponthediffa-sionofgeneralandcorrectknowledge hasbeendeeplyfeltbythosewhoaredesirousofintroducing1systemofeducationwhichembraces widerrangethantheordinaryroutineofclassicalinstruction.‘Thepopularwritingsofthosewhoacquireaknow-ledgeofscionceforthepurposeofteachingitdiffer inthemostessentialmannerfromthoseofaphilo-‘sopherwhodevoteshimselftothetaskofperspicuous‘Mustration. Howevercorrectmaybetheprinciples,‘andhowevercopiousthedetailsof«compiledwork,itmustalwaysbedefectiveintheselectionofita ‘topica,intheclearnessofitsreasoning,inthegen- 1a vasrac. comityofitaviews,andinthesuitableness ofitsillustrations.AmindlikethatofEven,whichfromitsinfancyhasbeendevotedtothestudyofNature,sclectsatoncetheprominentfeaturesofthescience‘hichitisproposedtoexplain;excludesallperplex~ ingandextraneousfacts,andcombinesundergene- rlviewstheimportanttruthswhichitistheobject ofthepupiltoseizeandretain.‘Thejustneasof ‘thisremarkcannotfailtobesdoittedbythosewho readthefollowingLetters,whichmaybejustlychar‘cterizedasthemostpopolarworkthateverwas‘written,andastheproductionoftheprofoundest Philosopherthateverwrote. Evian’sLottertoaGermanPrinoosswerefret madeknowninEuropebyaneditionpublishedby ‘theMarquisComponcer andM.Lucnorr,whoemricheditwithavarietyofnotes,andwhoseopinion(ofthewerkforthepurposesofpublicinstructionmayboacceptable totheEnglishreader:—“TheLettersofEvtxnto«GermanPrincoas,”saysM.Conponcer, “haveacquiredoverallEw rope1celebritytowhichthereputationoftheAw horthechoiceandimportanceoftheseveralsubjects, ‘endtheclearnessofelucidation justlyentitlethems,‘Theyhavedeservedly beenconsidered asatreasuryofscience,adaptedtothepurposesofeverycommen = vanrice. ry seminaryoflearning.‘Theymaybestudiedtead- vantage without much previous elementary know- ledge;theyconveyaccurateideasrespectingava- rietyofobjects,highlyinteresting inthemselves, or‘calculated toexcitealaudablecuriosity;theyinspire1propertasteforthesciences,andforthatsoundphilosophy which,supported byscience,andneverlosingsightofhercautious,steady,methodical advances,runsnoriskofperplexing ormisleading theattentivestudent.”‘TheEnglishreaderisindebtedtothelatoRev.Dr.Henny Hoxren forthefollowing translation,Whichhasgonethroughtwoeditions. Inthisthirdditionthetranslation hasreceivedveryessentialimprovements. ‘Theplateshavebeenre-engraved‘andmochimproved,andalifeoftheAuthorhasbeen.added,togethorwithvariousnotes,which,theeditor trusts, will beboth interesting and useful tothe reader. Independentlyofthegreatpopularityofthiswork, itpoasessesaparticularinterestatthepresenttime, inconsequenceofitscontainingapopularviewof thedoctrine,thatlightconsistsintheundulationsof anetherealmedium,whichisnowgenerallyadopted,|iconsequence ofrecentdiscoveries inoptics. moron,204July,193. © THE LIFE OF EULER - Lroxanp Evten,oneofthemostdistinguishedmathematiciansofthe18thcentury,wasthesonof PaulEuler,andMargaretBrucker,andwasbornatBasleonthe16thofApril,1707.“isfather,whohadbeeninstructed inmathe-aaticabythecelebrated JamesBernoulli, becamepastorofthevillageofRiechen,nearBasle,inthe Year1708;andassooneshissonbadarrivedattheroperage,heinstedintohim=fondnessfor‘mathematicalearning,althoughbehaddestinedhim forthestudyoftheology.Hewasafterwardsent totheuniversity ofBasle,wherehewasfound‘worthytoreceivelessonsfromJohnBernoulli,who wasafthattimeregardedasthefirstmathematician inEnrope.Theassidutyandamiabledisposition ‘ofEulersoongainedhimtheparticularesteemof‘thatgreatmaster,andthefriendshipofbistwosons,DanielandNicolasBernoulli, whohadalreadybo-‘comethedisciplesandtherivalsoftheirfather.John ‘Bernoullievencondescendedtogivehimonceevery weekaparticularlesson,forthepurposeofexplain- ‘ngthedifficulties whichheencountered inthecourse 16 ueo”RULER. ofhisstudies.Eulerhadnotthegoodfortuneto‘enjoylongthisinestimable advantage. In1723,he receivedthedegreeofMasterofArts;andonthis ‘occasionbeobtainedgreatapplausebytheLatin discoursewhichhedelivered,containingacompari ‘tonbetweentheNewtonian‘andCartesianphiloso phy.Attherequestofhisfather,henowbeganthe studyoftheology;buthisattachment tothemathe-‘maticswas90strong,thathisfatheraIstconsentedtoallowhimtofollowthebentofhisowngenius.‘NicolasasdDanielBerboullibaving,in1726,accoptedtheinvitation ofCatherineI.tobecomemembers oftheAosdemyofBeiencesofBt.PetersDbarg,promisedattheirdeparturetoemploythet{nflvencetoprocureforEnlerenappointment inthatcity.Inthefollowingyeartheyannounced thattheyhhadasituationinviewforhim,andstronglyadvisedhimtoapplyhismathematical knowledge tophysi-cology.Eulerimmediatelyattendedthelecturesof themosteminentmedicalprofessors atBasle,andmaderapidprogressinthestudyofmedicine."His‘attention, however,wasstilldirectedtohisfavourite‘Pursuits,andhefoundleisutetocomposeadisser-‘ationontheNatureandPropagationofSound, ‘andanotherontheMastingofShips,whichwaswrittenfortheprizeproposedbytheAcademyofScieacesin1727.Asthissubjectwasactually suggestedbyseveralmembersoftheacademy,with theviewofbringingintonoticethetalentsofM.‘Bouguer, whohadpaidparticular attentiontothetpbjettndwhowasthenprofesofbydrography intheseaporttownofCroisic,itwasnotlikelythat {UrsoFEULER. 7 Enler,whowasdestituteofallpracticalknowledge ‘ofnavalafairs,shouldhavesucceeded inthecom-petition. Bouguer,ofcourse,carriedoffthefrat ‘prizesbutEulerobtainedwhatiscalledtheacceanit, ‘orsecondprize,anhonourofnotrivialmagnitude,‘whenweconsiderthathewasthenonlytwentyyears‘ofage.AboutthistimeEulerwasacandidatefor‘thevacantprofessorship ofnaturalphilosophyinthe ‘universityofBasle;buthebadnotthegoodfortune tobeelected.DanielandNicolesBernoulliusedalltheirinfiuefencetoprocureanappointment fortheiryoungfiend;andbavingatlastsucceeded,theyrequested himtorepairimmediatelytoSt.Petersburg.Euler Joatnotimeinobeyingthiswelcomesummons; but,afterbehadbegunhisjourney,hehadthemortii-‘ationtolearnthatNicolasBernoullibadfallena victimtotheseverityoftheclimateandthevery dayuponwhichheenteredtheRussianterritory ‘wasthatofthedeathoftheEmpressCatherineI.; ‘anoventwhichatfirstthreatenedthedissolutionof theacademy, ofwhichshehadInidthefoundation.HavingreachedSt.Petersburg atthisunfortunateperiod, Euler resolved toenter intotheRussiannavy,andhadactuallyreceivedthepromiseof« Jieutenancy,andrapidpromotion,fromAdmiralSie- ‘vers;butfortunatelyforgeometry,achangetook placeintheaspectofpublicaffairsin1730,and EvlerobtainedthesituationofProfessorofNatundPhilosophy. In1783hesucceededDanielBer ‘noull,whenthatillustriousmathematicianretired intothecountry;andinthesameyearhemarieda 18 ireovxozen. MademoiselleGeel,«Swisslady,andthedanghier ‘ofpainterwhomPetertheGreatbadcarriedinto‘Russiauponhisretararomhisfirsttour.In1738,‘@veryintricateproblemhavingbeenproposedbytheAcademyof8t.Petersburg, Ealercompletedthesolutionofitinthreedays;battheexertionofhismindbadbeen#0violent,thatitthrewhimintooverwhichendangered hislife,anddeprivedhim‘oftheuseofoneofhiaeyes.In1788,theAcad- ‘emyofSciencesatPariscrownedhismemoir,ex- titledSurlaNatureofleaProprictésdaFeu;‘and in1740,hedividedwithDanielBernoulli,andoar‘countryman ColinMaclaurin, theprizegivenbytheftemeacademyforthebestdinertation ontheflax‘endrefluxofthesea.DanielBernoullihedtreated thesubjectwithasagecityandmethodwhichchar-‘acterizedallhisInbours.ThedissertationofMue- laurincontainedbiscelebratedtheoremontheequi- briumofellipticalspheroids;andthatofEuler ‘wasmarkedwithanimprovementontheintegral calculus,whichseemedtoresolvethefimdamentad ‘equationofalmostallthegreatproblemsonthemo- tionsoftheheavenlybodies. Inconsequence ofaninvitationfromtheKingofPrussia,troughhisministertheCountdeMarde-field,EolerquittedSt.Petersburgandwentto BerlininthemonthofJune,1741.Uponhisarr. ‘val,bewashonoaredwithaletterfromthekingofPrussia,writtenfromhiscampatReichenbach ;andtbewassoonafterpresentedtothequeen-motber,a princesswhotookgreatpleasureintheconversation ’ofitkatrious men,ShetreatedEulerwiththe areovauiEn. w tutostfamilinity;butneverbeingabletodrawhim intoanyconversation butthatofmonoryllables,she ‘onedayaskedhimwhyhedidnotwishtospeaktober!“Madam,” repliedEuler,“itisbecauseI havejustcomefromcountrywhereeveryperson ‘ThememoirsandworkswithwhichEulerenriched‘mathematios andphysicsaros0extremelynumerousthatitwouldoecupymanypagestogiveeventhe~ ‘briefestsceountofthem.Inmanyofhisphysicalmemoirs, Eulerhasbeenjustlyreproached forhaving‘ppliedthecaleulustothemostunfoundedphysicalhypotheses, ertometaphysioal principles whichhadotbeensuficiealy examined; andonthisac-countseveralofismemoirshavenovaluewhatever,excoptin90farastheyexhibitfinespecimensof theresources ofanalysis. HisDissertations on « ‘Windanilis, onAchromatic Telescopes, onNavalArchitecture, andonGunneryareamongthenum-beeofthovewhichareliabletothiscriticism,‘WhenEulerwasatBerlinthePrincessofAnhaltDesean,thenieceoftheKingofPrussia,wasde-‘soustoreoeivefromhimsomeinstructioninthe diferentbranchesofmaturalphilosophy; andfor heeusehedrewup:thepresentwork,whichwas translatedintomostofthelanguagesofEurope,and whichbasalwaysboenmuchesteemed,particularly fethesingularperspicuity withwhichitsauthorhagexplained soméofthemostprofoundtruthsinphy-sex.‘ThoKingofPrussiaoftenemployedEulerincalealations relativetothemint,andotherobjectseffinance,—in theconducting ofthewatersofSane 30 irkovvem. Souci,andintheexaminationofcanals,andother publicworks.In1744,Eulerwasappointed Directorofthe‘MathematicalClaseoftheAcademy,andinthesame ‘yearheobtainedtheprizeofferedbytheAcademy ofSciencesatParisforthebestworkonthetheory ofmagnetism.AboutthistimeRobin’sTreatiseonGunneryhadappearedinEngland,andthoughourcountryman hhadtreatedEulerwithgreatseverity,thisactofin~justicedidnotpreventhimfromrecommendingit totheKingofPrussiaasthebestbookonthesub-ject.Heeventranslatedit,andintheadditions‘whichhemade,hegaveacompletetheoryofthe motionofprojectiles.M.Turgotorderedthiswork tobetranslated intoFrench,andintroduced into .theschoolsofartillery;andaboutthesametimethereappearedasplendideditionofitinEngland.Tn1746,hepublishedhisnewTheoryofLig ‘andColours;andin1769,hismemoirSurleseffets duRoulisetduTangoge,gainedtheprizeoffered bytheFrenchAcademyofSciences.In1760, Euler went toFrankforttoreceivehis mother,whowasthenawidow,andtoconducthet toBerlin,whereshererosinedtillthetimeofherAeath,in1761;havingenjoyedforelevenyearsthe ‘assiduousattentionofafavouriteson,andthehigh pleasureofsecinghimuniversallyesteemedandad- ‘WhenEulerremainedatBerlin,heformedan {intimateacquaintance withM.DeMaupertuis,the feared President ofthePrussian Academy of ireoFEULER. a Sciences,andbedefondedMaupertuis’scelebrated ‘andfavoariteprincipleoftheleastaction,byresoly- ing,bymeansofit,someofthemostdifficultprob- lemsinmechanics.Inthedisputeintowhichbe ‘wasthutledwithKetnig,whobadattachedMau-pertusin1761,belostfoawhilehisusualserenity,‘andbecameoneoftheenemiesofthatunfortunate ‘Although thenymberofforeignassociatesintheFrenchAcsdemyofBcisnceswaslimitedtoeight,{otEulerwasappointedtotheninthplacein1768,fntheconditionthatnoappointment shouldtakeplaceatthefrstvacancy.1atheyear1760,theRussianarmyunderGene-alTottlebenpenetratedintotheMarchofBrandenburg,andpillagedafarmwhichEulerpossessed‘earCharlotieaberg. AssoonastheRussiangene- talwasinformedoftheevent,heimmediatelyre- airedtheJossby©verylargeeum;andupon ingnoticeofthecircumstancetotheEmpress {Bkeabeth,cheaddedtothisindemnityapresenof fearthousandflorins.Thisactofgenerosity,no doubt,badapowerfuleffectinattachingEulerto ‘theRussiangoverment, which,inspiteofhisab-‘sence,badalwayspaidhimthepensionwhichitgrantedhimin1742.Havingreceivedaninvita- tionfromtheEmpressCatherine, heobtainedpertmiagionfromtheKingofPrussiatoreturnto8t.Petersburg. tospendtheremainderofhisdays;but|iseldestsonwasnotallowedtoaccompanyhim.‘WhenEnlerwasontheoveofhisdeparture,PrinceCeartornicy invitedhininthenameoftheKingof F) iornvLEn.‘Poland,totaketheroadofWarsaw,where,loaded‘withKindness,hespenttendayswithStanislas,‘whoafterwardhonouredhimwithhiscorrespondence. ShortlyafterhisarrivalinSt.Petersburg,onthe 17thJuly,1766,helostthesightofhisothereye,hhavingbeenforaconsiderable timeobligedtoper- ‘withchalkuponaslate.Hispupilsandhischilrencopiedhiscalculations, andwroteallhisme-‘moire,whileEulerdictatedtothem.Tooneofhisservants, whowasquiteignorantofmathematicalknowledge, hedictatedhiaElementsofAlgebra,a ‘workofverygreatmerit,whichhasbeentranslated intoEnglishandmanyotherlanguages. EulernowscquiredtherarefacultyofCarryingoninhis‘indthemostComplicated anelyticalandarithme- ticalcaloulations;andM.d'Alembert,whenbesaw himatBerlin,wasastonishedstsomeexamplesof ‘hiskindwhichoccurredintheirconversation. ‘Withthedesignofinstructinghisgrandchildrenin theextraction ofroots,heformedatableofthesixfirstpowersofallnumbers,from1to100,andherecollected themwiththeutmostaccuracy. ‘Twoofhispopilshavingcomputedtothe17thterm,acomplicated converging series,theirresultsdifered‘oneunitinthefiftiethcypher;andanappealbeing.‘madetoEuler,hewentoverthecalculation inhissind,andhisdecisionwasfoundcorrect.Hisprincipalamusement,afterhelosthissight, ‘wastomakeartificialloadstones,andtogivelessons ‘onmathematics tooneofhisgrandchildren,who ‘seemedtoevinceatasteforthescience, ureoyEULER. 2 In171,adreadfulfrebrokeoutinSt.Peters: arg,andreachedthehouseofEuler.PeterGrimm,«nativeofBasle,havinglearnedthedangerinwhichhislustriouscountryman wasplaced,threwhimselfamongtheflames,and,reachingEuler's‘apartment, broughthimoffonhisshoulders,attheriskofhislife.Hislibrary,however,andhisfurni- ‘turewereconsumed ;but,bytheactivityofCountOrloff,hiaMSS.weresaved.‘Hoavingrevisedthelunartheorywiththeaidofhis00,andhiscolleagues KrafftandLexellbecon-structedasetofnewlunartables,whichappearedin1772.Thesetableswere,athesuggestionofTur-{g0t,rowardedbytheBoardofLongitudeinFrance;‘andwhenthemoreperfecttablesofMayerobtained‘thegreatpremiumofthreethousandpoundsofferedbytheBritishparliament, thesumofthreehundredpoundswasgiventoEulerforbavingfurnishedthe‘theorems madeuseofbyMayerinhistheory.Intheyear1778,Eulerpublished,atSt.Peters.burg,hisgreatworkontheconstruction andman-‘agementofvessels.Aneweditionsoonafterward ‘appearedatParis,andatthedesireoftheFrench ‘Kingitwasintroducedintotheschoolsofmarine, andarewardof1000roblestransmitted totheauthor,accompanied byahandsome letterfromthe‘celebrated Turgot.AboutthesametimeanItalian,anEnglish,andaRussiantranslation ofitappeared,‘andtheRussiangovernment presentedEulerwitha‘ftof2000rubles.‘ThreeofEuler’smemoirsontheInequalities intheMotionsofthePlanets,werecrownedbythe “ LaveoFRULER. FrenchAcademyofSciences;andhealsogained theprizesof1770and1773byhiaperfectionofthelunartheory.Havinglosthisfretwifo,bywhombehedthin-teenchildren,eightofwhomdiedinearlylife,he‘wasmarriedasecondtime,in1776,toMademoiselleGeel,themuntofhisfiatwife.‘Eulerunderwenttheoperationofcouching,which‘wasatiendedwiththehappyresultofrestoringhissight;butwhetherfromthenegligence ofhie-sur-‘ge0n,ofromhisbeingtooeagertoavailhimeelfofbisneworgans,heagainloothissight,andsufferedmuchseverepainfromtherelapse."Hislovefor‘science,however,continued unabated, and:in.the‘courveofsevenyearshetransmitted seventymemoirstotheAcademyofSt.Petersburg. Onthe7thofSeptember, 1783,afterbavingamusedhimselfwith‘calculating uponaalatethelawsoftheasceneional‘motionofballoons,whichotthattimeoocupiedthe‘attentionofphilosophers,hedinedwithhisrelation MzLoxell,andspokeoftheplanetHerschel,and ofthecalculations bywhichitsorbitwasdetermined.Ashorttineafterward, hewaserusinghimselfwith‘oneofhisgrandchildren,when,onasudden,hispipe fellfromhishand,andheexpiredofanapoplectiestroke,inthe79thyearofhisage.Eulerletbehindhimthreesons,havinglosthis‘twodaughtersinthelateryearsofhislifTWwenty-sixoutofthirtyofhisgrandchildren werealiveat eehe‘Afteralonglife,sosuccesefillydevotedtothe ‘einnces, Exler'sreputation wasverywidelyem : ayeoFxULER. 5|tended:Besidesbeingaforeignmemberofthe|AcademyofSciencesatParis,howasaFellowoftheRoyalSocietyofLondon,andbehadreceivedfrommostoftheprincesofthenorth,withwhom‘bewaswellacquainted, themostflatteringmarksoftheirestoom.WhenthePrince-royal ofPrussia visitedSt.Petersburg, heanticipatedthovisitof Eoler,andpasoodseveralhoursatthebedsideof thisgreatman,holdinghimallthetimebytheband, ‘andhaving,atthesametime,uponhiskneeoneofEuler'sgrandchildren,whohaddisplayedaprema tureattachment togeometry. ‘ThedeathofEuler ‘wasconsidered as&publiclosseveninthecountrywhorebelived;andtheAcademyofSt.Petersbargdecreedtohim,attheirownexpense,amarblebust,‘whichwasplacedintheirpublichall,Inanalle-{goricalpicturewhichtheacademyhadputupduringhislife,Geometrywasrepresented asplaced‘ponabasementcoveredwithcalculations. ‘Thesecalculations weretheformuleeofEuler'sTheoryoftheLonarMotions,‘Euler'sknowledge wasnotlimitedtomathematics‘andthephysicalsciences. Hehadcarefullystudied‘anatomy, chymistry, andbotany,andhewasalsodeeplyversedinancientliterature. HecouldrepeattheRancidfromthebeginsingtotheend,andhe‘couldeventellthefirstandlastlinesineverypageeftheeditionwhichheused.Inoneofhisworksthoreisalearnedmemoironaquestioninmechanics, |ofwhich,ashohimselfinformsus,averseoftheBneidgavehimthefirstidea.lerpostednatal«strongeontitons 6 UreorEULER. ‘undwhenwoconsiderthenatureofhisstudies,and theassiduitywithwhichheparsuedthem,weoan- ‘notfailtobesurprisedatthegreatdegreeofhealthwhichheenjoyed.Inallhishabitshewassober ‘and temperate,—in hismanners uneffdcted and plessing,—andinhistemperlivelyandcheorful.In hismoralandreligionscharacterthereismuchto‘admire.Thehighfamewhichheacquired,andtheinterruptions whichhemusthaveexperienced, bothatBerlinandSt.Petersburg, never’inducedbimto ‘abandonthereligiousdutiestowhichhehadbeen‘educated. Aslongashepreserved hissight,he‘assembled thewholeofhisfamilyeveryevening,andreadachapteroftheBible,whichbeaccompe-riedwithanexhortation. ‘Theologywasoneofbis favouritestudies,andthedoctrineswhichheheld worethemostrigiddoctrinesofCalvinism.‘ThefollowingisalistoftheprincipalworkswhichEulerpublished in©separateform.His‘papers,whichappearedintheMemoirsoftheAcad-cemiesofBerlinandSt.Petersburg,areextremely numerous;andheleftbehindhimnofewerthan feohundredreadyforpublication, inordertofulfil 1promisewhichhehadmadetoCountOrloff,tosupplymemoirsforthe‘ActaPetropolitana fortwentyyearsafterhisdeath.DissertatioPhysicadeSono.Basle,1727. Mechanica, sivemotusscientiaanalyticeexpovite,Petropoli,1736,2vols. Tentamennovetheoriamusica.Petrop.1739. Thisworkcontainsmanynewviews;bul,asM. Fassremarks,ithadnogreatsuccess,asitcom uraorxutes. ” txinedtoomuchgeometryformusicians,adtoo suchmusicforgeometers. sai propria Lausanne,1744,sto. 1744,2vole.Sto.Thiswork,whichbadbecome veryscarce,waareprintedatLyonsin1707.Tt ‘TantranalatedintoFrenchin1796,byJ.B.Labey, andpublishedatPars‘Theosmumplantaretcontaran.Bero-fini,1744.Opwaclavariargument. Beroln,1746, 1760, 1761,8volsinSto.Thetablesofthoaunand soon,whichazesometimestobefoundseparately, formpartoftheIatvolumeofthiscollection.AB thethreevolumesmakeonly600pages,theyaregenerallyfoundinone. ,‘Scientianavais,eutractatesdeeohutruendis acdegennonin,Pezpo1749,2vat iomoheumLamasechibensonescorporem ineyuaitescomadditamento. Beran,1768,41. qualiaescomaditement-Berlin,1789,to. camesomineobjections Cl.Koenig,contrahotpriacipionfclarem."Berolni,1768,8to. 1766."Anothereditionofthisworkwaspublishedin1797,in2vol.dto,andanotheratStPeters |bargin1604,in2vols.to.‘Constructo lentoobjectioaram eaduplicistr.Petrop. 1762.‘Madiationes de onemotescometoram Ey naveoFRULER. Rostochit, 1765,4to.Tnstilutiones CalewkiIntegrals, Potrop.1708-1770,8vols,4to.Anotheredition,morecorrect, ‘waspoblishedatSt.Petersburgin1792and1794, in4vols.Ato:Perop vs Dioptrica. 1760,1771,3vols.4to,‘NovaTabula‘Lamareesingularimethodocomstructa Petrop.1772,Bv0.Opuscula: Analytica. Petrop. 1783-17885, 2vols,4to.ExtirendunePrincease@Allemagne sorquelquesanjetsdePhysiqueetdePhilosophie, St.Petors-burg,1768,1772,3vols.8v0.Anotheredition ‘waspublishedatBernein1778,in3vols.80,AnothereditionwaspublishedatPariawithnotesbyCondo,adantherin1819,byJ-B.Labay Elemens@Algibre,troddoVAllemand,parJ. noull,avecdesnotesparLagrangeotGarnier. Paris,1807,2vols.8ro.‘Twoeditionsofthiswork watepobaodatLyonin1774ad1796andan ditionappearedinLondontranslatedintoEnglish. +Theoriecompletedelaconstruction efdelama-eworedeavaiseous(lostyleretouchéparKeralio).asin1776Gro,|Theoigialedtonofthiwork atSt.Petersburgin1773. CTaeBale ‘appearedatBriennein1797,in18volumes. ‘Amoreextendedlistofthewritingsofthisillus {riousmathematicianwillbefoundinhisEulogéby ‘NicholasFuse,whichwaspublishedatSt.Potora- burg,in1783,in4to, LETTERS: ' DIFFERENT SUBJECTS » NATURAL PHILOSOPRY. LETTER 1. OfMagnitude, orExtension. "Taxhopeofhavingthehonour40communicate apron’mayfewonsi Dedoming moreandmoredistantwhich{5avery fernblerican Yomoy{eelmye inetd {eisupnlypersonaltractionbywriting,fara3“8Baty tempbyantagotoformaue es(orm 2acaAMagninades producing, asexamples, ihe smallestaswellasthegreatestextensions ofmatter Sipdincorenble tingolemofheuaere And,first,itisnecessary tofixonsomeonedeter- intidiasieofmowdere,obvines tooeoneeey Siofwhichwehaveanexactteathalof8fortierimitne, Toeguyoftasoteriba titers fotheyeilxloo |Gleat‘orsmsthoformer,bysnceiinag’toe manyfeetitcontains,andthelatter,byascertaining wlpartoffoteamretorbarntee » osonore, ofa, wehavethatalsoofitsAalf,ofitsguarter, detrei oftga,selagemmasaakeresolinenhatoeama ‘marked, thatthereareanimalsnotofgreaterexten-aticerssrc | ‘ever,arecomposed ofmembers through whichthe |SuSri plnnce. Seedcremeot etheraohm Se ore enSS sommes,untmelecmBe ‘tion;andthattheseagainaredivisible intopartser ea a spectsmalTporcram, ‘ight,and,comparedtous,ceasestobeanobjectof ‘sense, itneve surpassesinmagnitudecertain complete animals, andmusttooneofthoseanimals,aehay . ‘. TheeeeemeFessoomexemineeaeparksas heaarnVoroe Moontheeatenmga,Younerote coeeeetanniet©aneees ESTSuptie ceeimai sophanced tusdicenropeofenPianeta Presoarstioned a resteomeEGatMaeda2tefereae pantoNegler9OkeoeSaSrstiemoratenee caehace Sereareas ‘oftheearth,whenwearetoldthatits. ferencefee ae ierentisbutssem0 mle._AngJimlanaDing§ Sereees Fe Pena tet (om Exranston. a {forwhichreasonaloowogivoitthenameofglobe—thediameterafthisgiobeiscalculated tobe7004‘miles;andthisisthemeasurementwhichweemploy fordeterminingthegreatestdistancesdiscoverable {inthe‘heavens.Ofalltheheavenly.bodiesthe |Moonisnearesttous,beingdistantonlyabout30‘lewor8864000fet;buttefretcomputaon‘miles,oF1,938,400,000feet;butthefirstcomputation (of30°diameters oftheearthistheclearestidea. ‘TheSunisabout400timesfartherfromusthanthe‘moon,andwhenwesayhisdistanceis12,000diame-{ersoftheearth,wehaveamuchclearerideathanifitwereexpresoedinmilesorinfeet.‘Youknowthattheearthperformsarevolutionondthesuninthespaceofa_year,butthatthe Sunromainefixed.BonidosthoEarsthereareten‘othersimilarbodies,namedplanets,whichrevolve Toundthesun;twoofthematsmallerdistances,‘MercuryandVenus;andeightatgreaterdistances,namely, Mars, Ceres, Pallas, Juno, Vesta, Jupiter,Saturn,andthoGeorgianSidus.Ailtheotherstars hichwose,cometexcepted,arocalledxed; ‘theirdistancefromusisincomparablygreater finntatofthewun"Theirtancesarone ‘veryunequal,whichisthereasonthatsomethesebodies greaterthanothers.Batthe‘earestofthers,unquestionably, shove8000times ‘moredistantthanthesun:itsdistancefromus,accordingly, exceeds45,000,000oftimoetheearth'sdiameter thatJs,388/80,000-00 mile;andthismultiplied by6980,willgive tation exprenedinfooAbdthisherleis ‘hedistanceonlyofthosefixedstarswhicharethenearesttoue;—themostremotewhichweneearePerhapsahundredtimesfartherof.*Itisprobable,thesametimethatalthewesaretakenLogthar constitute only&verysmallpartofthewholeuni-. gee athe sont tnt—der, = ormsc verse,relatively towhichtheseprodigious distancescptraterhanagrinofetdcomparedothe SERear rere Ses,stone roeae Layla Yay, ureasemyatyourhimemaybo miaonerabepaigeerane wyattceeweenee otreyrchecoeoefirearmSeireereperatee‘velocity. Lettwopersons, theoneonhorseback,Bhpireeenreaoeereimmense anescermecar Beilies esroe giantgreancnego cetareSeeants Se locity!‘Theroadisthesametohimwhoridesand ageaeate oat fecinoatteety irdeTonkoerneem fecece,teren,gtmeanhe SireRagesSemeretote atmBraMaheoat of Seeteehoeeerene iratesemeements at Eelamceete ieeedBeoarteemployed. Abody, therefore, whichinthesame SeoeredAtay ehaeceSmee Spee orvavocrry, a timeitpansesthroughthricethedistance,itiseaidcomprehend, then,theelyofbody,whenwe ‘of&body,whenwe SeIiormedoftheapacethroughwiipanes it'scertainquantityoftime,"Inordertoknowte elociyofsypact,whenIwalktoLyizow,(abut ‘leaguefromBevin),Thaveobservedthat1maka 490stopsin&mint;and.oneofmystopeisequal totwofectandahalf"Myvelocity,thoo,iseuch ‘asfocarryme300fostinaminute,andspace60timesgreater,of16,00fectinanhour.Wore‘therefore, towalkfromhencetoMagdeburg, itwouldtakeexactly94hours.Thiaconveysanaccurate ‘doaofthevelocitywithwhich1amabletowalk. Nowitiscasytocomprehend whatismean!by&fFesiororiessalocity Forifcourierwore1 Thenceto in19hours,hisvelocity Toldbethedoubleoffue;ihewea!Insight Tours,hiaveloetywouldbetriple.Weremarka {rygreadiferenceinthedograeofvelocity.”Tho {ortoleefurnishesanexampleofavelocity extremelysmall.Ifsheadvancesonlyonefootinaminute,frvelocityx00tienIoshannefTae‘ce3fotinthesmoime,"Wearelowing oquainted withvelocitionmuchgreater.Thatof {hewind.admitsofgrestvariation. Amoderatewindgoesattherateof10°feotinasecond,or600Footinaminute;itsvelocitythereforetsthedoublo(ofmine.Awindthatrane90feetin@second,ot1200inminute,iaratherstrong;andawindwhich ficsattherateof$0fetinaseconds extremely Violent,thoughitsvelocityismeagreatet Thanmine,alwouldtaketwoYoureandeny- fourminutostoblowfomhenoetoMagieburg.* "Thovelocityofsoundcomesnext,whichmoves1143feetinatooond,and68,800inaminute.Thisvelocity,therefore,is299timesgreaterthanthatof siyataleesa arineswelaro uM OFSOUND,ANDFreYELOCTTY. mypace;andwereacannontobefiredatMagde-BurgithereportcouldbeheardatBerkwordcele gaoementeecntor Sots Ceara AesHeermere,bees Heaedrnsoeigenores ePaeeiiremennmeearyEatceeameat SAREUioraramet SoS ees apseionseameifiamice sae aioe ae Pointofitssurface,then,undertheequator, movesEAST hlsartenSe Beene Seinen Smee hearin ora arteEeitarara sfrieeniapeti ieee Reetiee manscutee Gees Sapna eaalaeee Pela ReoeryeetSitariiamenetee aie=erae Sapam varaOfntPy.arent eteon fyingsarymeforwardtotheexamination ofsound,ofBe tet is ema can SeSeeineeet tes Smisek tesapmame, rrpation1cutiefomtnpreareho eeeScreen reyhaenrere Sebergee : STL cEtoawhoawade santsaatthrenters pengappticeomeingeer weraeas taabeen ereeyahSoe rn aSeSe Sane SET NT ceeBrigercette eeere erate denies eycele ate eteey enent eySea td apr rer feaanonanyO ‘ducesit,assmellisemittedfromtheflower,byfll- Suton acineoe igea racoice erly entertained;butitisnowdemonstrated, that aat innocent raped fonealceptngpcicored ference elecymereminyoes Sorantiterweeee irenerompeeeeee ih net Toact Sepa eso Meaa ore eocest saagitggatteepasBrisF |Seatsepraiesmene!winA,B pasecealternatively Fg. foereeeeeANBBeko! 26orsoomxoresvazocry.meshcntigoftteaBeharinzeetnteSycometeat"oupf Sra cope ftmorenoespeeof hearing.Itistheair,then,whichreceivesthese See htent eae eresacdtatepapofSo «Rie reeesteprezofwon Rcbaais APScomedy e SreySomaeee weeSearedctwmeeotecooesirae ee ea eeSear cameneatieeeeeeeettid ‘apefeeSahacle hesestrokeseucceedeachotheruniformly, ‘orwhentheirintervalsareallequal,thesoundSra era oraloeee BiuehsrounteroteBetestgeatesaeanron oeaecamelseatamenore aeeeaa Sone ister caaok iarheuervinioalarecle daiates eed Senger rakesapnb oe odesectoSarees eestee, ereCeee ereee PEOeels Smee oemoefarcomadttsenoe eosStaph Biantah segcrantany Aeonheoraowereee crus cloverSeyHagantether,Nebrors SeokasZoiretokenfhefeo oF consouor sno mitonancr. 37 leeheahowocombiesoundsdiftreninrexpectStatestdserenash9aa Roomsarvetleharmony.inhetsand srefoer rire nemuneietathesharpouie! alercyeyfheston |containscertainanddeterminate numberofvibra- +Soewhee comple apc"poemae byShen Cat neyoe Beadonensschonantenoeasicdsee Teowiratooni mmespaceofie’"Aaap ses lei tes insecoud ige okScitenoteC+antirissn’olyBiles, ieotewuldbelowerormora. atwive tooureu, there arecoat ins beyoshShiensonadinolongerperoopible tead That weneneni eCniing SeteanotssagwichoanekSo brationsin@second,becauseitistoolow;orthat fFesingwhiehwandmanemarehea8‘ooo,biaesuxatewoldoeign Seah Apa, en were1v. OFCramerendDisses 1somesmyrearthtonbeating«snp smosiedl sound,oureatisrockwith’seriesof Soke cgi st from teh ter, tee gRtBeY andamber ofwhich,inagivenspaceof SeePronriate te dees cholesfetaowenshhsatteato inbor ofrations eroes odie ages to ty sreon, te lowe eae at pote aid fhe’ gree themonte of0 vit ap anoma Semenete me 28 oF consonanceaxbussonance. tonsthehigheristhenote.‘The oefinomaniflcounmyteretore,becompared tow seriee ofdow equidivant from each other,aoeaeneitheintervalsbetweenthesedotabe .ireaterorsmaller,thesoundproducedwilltelowereThigher. Ircannotbedouble,thttheperceptionOfasimplesoundissomewhatsimilarorana{0theaightofwuchaserieofdotsequidistantfromteachother:weareenabledthostorepresenttotheyewhattheearperceivesonhearingsound.If{hedistancesbetweenthedotawareBotequalor‘weretheeedotsseateredsbourconfusdly, theySotllie'areoretenaton ofconnednla,i ‘Sonsistentwithharmony.”‘Thisbelngiiddows,let {tsconsiderwhateffectwosoandssmiledatonceBotprodacenear.Fmendenttak vosoundsare.equal,orifeachperformsthesame Senteroeosintheamentheouwi intheverysamemanneraobya otecadinmeiothestwonotesaretldtobe inunison,whichiathesimplesteccord:we.mean bythetenneccotheblendingoftwoormoreepectoflowendhighreshallporootveist ot weshallperceiveamize Satofwoerieofaresienhofwhichie Intervalsareequalam venbatieoneantheoehereirintervals corresponding tothelowernote,andthesmallerfo SheMgr.Thunmisaothnaccordoffrea: froseries OrdotsatangedontwolinesADita6D Ts ee be 788101 a anes} - iasibGGiboni andinordertoformajutidenoftheetwoseries,emt havelnpeepofheorderwhch Subeietsamongthem;\or,inotherwordsofthere- {tionbetweeatheinteresoftheoneinesndofthe or comonaner aro wesoatcr. 38 se, vn ete nlme otSracs arb et ont |eae eeeehete rele Neesratgycoro Screen ci sere Seu reese egosSadigri tecture fe ese ase ee ete figure, sn taht pce int ipaSeaecmeSememr Stee Pi eestonee discover theorderwhich subsists betweennari eeseaaneee sahae eiirae pein ve mln ded mesoneasctiraeeach et aeesoa some! wircoas, inthe:preceding cna,itwenex Hy io, rai Seringbetween twonotes,theiraccordisdenominated erm ko eer ea ik ae eae ere coenacuhe iver "areata precisely anoctave harmonize soperfectly, and Re oem, ee eo come arn oorarastesthomWyfnseites.mseBiBin mettenyySemmebion, SernoteSrharee eenee te sce eeae Sia”eee cevaae Sain fis acat res an emer enti endo a er Sesae 7©Cann oars orbrebythtnsoma,tatthsomd lg ata Stee cert tt eset Eanlyperceitle. Thus,beingtovchedthekey markedFatmorkedf-whichisanoctetehighe?, ‘ineasilyattunedtoEs4thejudgment oftheear Mgmttend0een ea oni, Mine agchek ene netabe Spasareugar aamatey eee nn gern ora Se ee ner eee ae SREterials ieeo” trehaaeae Fee Aras ‘ge mae on be,EROS aMaeeancay ae en a Primed eb pla raseperticeveearonnie eg titan snes fe eae, Ey SitBeandseaatetedseermade: Itisthis,thatnoteFandnotefmakeanaes etoeEaere oF vmwox AKD ooraves. a Isprecisely doublethatofnoteF.Inordertohave theperception ofthis accord, you have ouly tocon- det the proportion ofone totwo, which, ai ic any wrtntheyebythereprint ofthefoeFormer empyedafecte heearn «watpact.Youorleoalyeames,teat ‘moresimpleanyproportionisor 7 tinal!numbers, themoredsundy tpresent itself {otheunderstanding, andconveys toita.sentiment‘Ofaatinfaction. Architectslikewinecarefullysttend to‘this maxim,astheyuniformlyemployintheir orksproportions assimple’ ancrcumatance per. Sit,“Bieyuallymaetheeightofdoorad‘indodoublethbentancraoe Dretadtyealumber,cainethsinobvious Enigratelulto theunderstanding. Tho same thingHolagoodinmsto:acortyareplaningonlfact themdperceives herelation ingKronen hesound adireaton i69mock moreeasilyperceptitensitisexpresodbya mimbere. ‘Now, nextt0therelation ofequality, ‘hich denotes fwo sounds inunison, the ratio of Twotooneisundocbtedly themost simple, andtin {his which faraishes the tccord ofan octave: hence Iinevideng, that thisaccord possesses many advanetagesaboveeveryotherconsonance.” Having this ‘explained theaccord, ointerval oftwo notes. do- nominated bymusicians anoctave lots considertoveralnotes,asF,{vxteachofwhichivanc= lavehigherthanihone.immediatly, preceding; sincetheatheinterval ofFfromf,offfom’ of7 from of7fromffaanoctave,theintervalofF 1077 wil beadouble octave, that ofFto 7tile fetave,andthatofFtoaquadrupeoctave,Now, wile note Fmakes one vibration, note fmakes Tro, note r'makes four, note7makeneightand sgmakessixteen:Bencewesee,the!asanOc- ‘vecomeepondeintrltonof1022double i (2 on oma sno ornare ‘octave mustbeintheratioof1to4,atripleinthatof1to8,andaquadruple inthatof1to16.AndSerietinotteva ttT BreeMoeasreallystethetyeeeHoseStessayperceptosearaeglepeolirept gn pitbib'outeors. When,terol,Saagasiehord,youhavefixedthenoteF,itisnot80‘easytoattunethedoubleoctave7asthesinglef; STZAGIN Qa estanhetscolores Sodgantwitnghoughoeine teatoven."ThewesettteitewiecomBeenieihetermcomonnce, tdtof Wiseisnontnetheymaybangeaac ingtothefollowing gradations= 3Romario HERCESSaneme 5Recaumonna vee ‘VEDegree,ubequaatujeoctave,inthatof11038. And goon 8Jong 2snd apereptle. Sacharetheaccordedenominated cansonances, totheowiege afguchwehveertana cone Head ih we"ksow atlg ot oar arses comp Gi ae Mies cnaayetingte Bator cee aeExplanliotoftees] mustaddonereatrexSPU iteenioetae Poe .Mitte ction trieshoroeutors lac fae other You ee the reason ofa Sec somo hehapchor, hey Sodl dates lore yousve te ocate 6BERGABcsbe“fogiashesath,reckeShingthee?AnadvoSobendsons . certain seriesofmusical Intervals, theature ofScala cakedateatowayate, ‘34May, 1700. oF ormrn consomances. a LETTER VI. ]Ofother Consonances. Irmaybeaffirmed, thattherelationsof1to9,of 1toAol108,of11016,whichwehavehitherto Considered, and which contain the progression of ‘octaves, apallformed bythenumber9only;since is'9 times9;8,3times4;16,9times&|Were we toadmit, therefore, the number 2alone into|Misi,eauariattheKnowledgeofoly |the"accords ofconsonancee, which musicians callthesingle,doubleortripleoctave;andaathenum-ber307itsteahliation,feminhon onythetum.tere816,3064th,onbeingawaysdoubletheFrcnligallother nmoerswouldremainankaown. fow, didaninatrument contain octaves only, asthe notes marked C,c, 2%) and were allothers ex- €luded,iteonld notproduce anagreeable misic,onne- fountofifstoogreatsimplicity. Letusintroduce, then,together with:number the‘number ke: wwise,andobuerve what necords Orconsonances would Dorthe result. “The ratio of1to3presents atonce two sounds, the one ofwhich makes3timesmore vibrations than the other inthe same time.” ‘This ratio iundoubtedly themost exsly tobecompre:|hended, nexttothatof1to2;itwill,accordingly,| famish’ very pleasing consonances, bitofanataretotalydierentfromthatofoctaves.Letussup-Perstheshatntheproportion of1103,number ‘corresponds tonote €,since note¢isexpressed tynumber 2,number 3gives asound higher thaneatthesametineverhanoiewhichere tonumber4.Now,thenote Fibthattowhichmosichnsafttheletteraed theydenominato theintaral fomclogah bocauseinthekeysofaharpsichord thatofgisthe “ crruse comamancay, fhfomc,a8¢dfg.Ifthennumber1 ducesthesound©,amber2willgiveeynuhoer dare frome the oe7a8poteea tacelts ofgrtheuber coneopondiog toBeritmee Ser"RisingslenSetanesthesoundFre conepont toa nner Sic gesier oat aori Wenoteswthwhich thetonaabers 3‘and3furnishus,indicating noteCby1,therefore,are, Gogeet eo1988,8,1,1. once ita dear thn thettioat 1103 expreseon antoral compounded oan octave avd anyfatathtinteralonaccountefhesimplicityof ‘femmewhichroprosetInarabeymaxttanecient. a” Mon oeterd cond nkumongeconDancestotheAth:andtheearcatchesit86easily, Thatthereenodiicultyintuningithe“Porasfreon oi thourtninyhe lowest’beingg,thesecond2,thethirds,and’the fourth33°andéverymusician patsthemintuneby iberear ‘only. A Hy howeteris not a0essiytunduetgctsbaheEveheoryT'1o8i»moreperceptible thanasimplefith,a8 fromtsvorfometo,wichapreted oy theproportion ofto8:Sali'skewise Knows byebptionces that faving Sued thenote Gis Chole ator totteMgher stg thar 66ate fieG.I uny had man themofo Fnumber 3 Would mark hg ago Tso that F,212.4 ©wouldbemarkedby 2546.613,whore,homfie©theinterval lavahe nthovedone?s ora: kontiehom Tioaeloith,astheratiooft6andof8 1°55,Ithesameanthatotfo4.Rorowe Btringsperformtnhesamelime,theone4ibn tions,theother6,theformerstringwillmeke,ina nga nomk erormmconsoraxces. ry timoequaltohalfthefirstspaceoftime,twovibra- tions;andthesecond, inthesametime,willmake three:"Nowthesoundsemittedfromthesestrings arethesameinbothcases;ofconsequence, there- Iationof4to6expressesthesameintervaluxthat Of 21058, that ina Ah. Hence wehave arrivedat theknowledge ofanother interval contained intheratioof8to°4,whichiathatofto";andconse urna of0oFofCfoF.“Moncane cll aJowih; hndbingexpreeed bygreaternumbers itisnotsoagreestyagreatil,asthefifth, andsillles80,=octave.Number3havingfarnishedtusnewaccordsorconsonances, namely.fhefithandthefourth,beforewecallinanyothers,Jetusfakeifagainthreetimes,inordertohavethe tomber9,whichwilgiveahighernotethannote ‘$,orzone octave and one fifth. Now, 7istheoc- fave of7,andy theAh of7;number 9then gives‘thenote7,#0that{|%,Zwillbemarkedby 6,8,0,12; and ifthese notes be ' taken inthelower octaves, therelations remainingthesame,weshallHave,GRGe Gg oh BRB 6,8,9;12,16,18;94,39,36;48,64,72;96;which leadsustotheknowledge ofnewintervals.‘ThefretisthatofFtoG,containedintheratio of810.9, which musicians ‘all &second, oFfone, ‘The second isthat ofGtof,contained intheratio of9to16,calledaseventh;andwhichisonesecond, gasionentanaoie.”Theepropetons, beingalreadyexpressedbyverygreatnumbers, fotfeckoned among theconscnances; andmusianscallthemdissonancesordacords ‘Again, ifwe take three times the number 9,or 1,itwill mark tone higher than ;,andpreciselya fitshigherthang,itwillbeaccordingly hetone2, ‘anditsoctave7willcorrespond totwicethenum- bar97,or64,anditsdoubleoctuve7totwicethe “6ovTHETWELVETONES | number54,of108.-Létusrepresentthesetones sometanaower,themannerlowing: | cGDF Gig & &B;& iS M4,27,32,96;48,5h6,‘72;96,108,198,Be 4hgs146193,216,256,2885384,‘Hence wesee,thattheinterval fromDtoFiscontainedintheratio97to38,ndthatoftodintheratioof39to64,thetwotermsofwhicharevieby.2;andthen,iplaceofthinrelation,‘we have thitof 161097. "The fist intervalincalled 1treeminor,orltrthird,andtheothergreater firth, ‘The nuraber 27mightbestilfurthertulti- Bitty3;Btonic,tendno0fa,andwe mitourselves tonumber 27,resulting from 3mule tipled three timesbyitself:othermusicaltonesati ‘wanting areintroduged bymeans ofnumber 6,and hallbeexplainedinmynextLetter. ‘4dMay, 1760 LETTER Vi. OftheTheeoeTonesoftheHarpsichord, ‘Tae present subject ofmycorrespondence withyourhighness istodry,thatIbegintoapprehendit naybegrowingtiresome. "That1maynotwasteigomuc inn adtyrevd fomhenee yofrecurringfrequentlytoatopic60uninterest.ing,Isendyoubythisconveyance threeLettersatonce. "Myjtention inundertaking itwas forender Tibitherealorgofmusical ater,wihwhich Invsicians themselves. are almost. totally. ‘unac-eae,innokoeheorytheyareindeedforkpowleeofaltheesoundsbutraterthe tccretpowerofgenuineharmony; operatingsoef taciounlyontheirearsthatthey’havebeencon- ~ { re ) or THE manencwonn, a |trained,if1maybeallowedtosayittoreceive {onesactuallymose,thoughtheyarefothitherto Fefecyagreedrespecting thetetdeterminationpricifesofarmoryaretlimatelyreduc tomcmbersas havedemooaratedy andthasbea emarked, thatthe pumber 3furnishes octaves only, bothat having fixed forexample, thenote F,weate conductedtothenoies(.r£7.‘Thenumberafer- ‘wardfurnishesC,c,2=,whichdifferonefifthfrom Thepreceding series; andthe repetition ofthis same number 3finishes! again theathe oftheSox namely, Gz 57:tndfinaly, thethird repetition ofthis number8addsfurtherthenotesDydy?- |Theeinciples oftary then,bingtached fo timplleity, seem toforbid our pushing father the repetition ofnumber 3;hitherto, accordingly, we {eteonythlowingottoeachoct 16,18,‘94,97,39;whichomtaialeletfur. ‘averycopious music. Butletusiatrodueo, in Mddition tothese,number 5,andobserve thetone ‘hich ehall emit ‘ve vibrations wile Fenuits only dues, Nowfmakestwovibrationsinthesamefie ‘Takes fout,andsix.Thenoteinquestion,then, Inbetween 7and 2. Its thal which musicians in? dicatebyliters,theaccordofwhichwithnoteIsAenmiatedafresterdandsfoundYoprodice |averyagreeableconcord,beingexpresed!bythe ‘ery wimple ratio of4to'8. Parthen, note +with Tot produces anaccord contained inthe ritio of 50.6, whichis almost anagreeable asthe former, | fodwhichis deaotninated ser thin, represented iytheratio of97to9,and itsdiference from the Batenatpercep teear.Thisamenumber 8bingapi totheothernotes6,64 tril give us,ih ikemanner, their greater third, {kein theSecond octave below, tha istoaay, thenotes«andP,which,beingtransposed, willgive “ ovTauTwaivsTomes {he,fllowingnotes,withthercorrepondingem RF, GABoo df 188,135, 144, 160, 180, 169, 216, 940, 950, ‘Take away the notes Fs,and you will have the incipal touches ofthe harpaichord, which, accordtotheancients,constitutethegenusdenominatedddstonic,resulting’fromnumber2,fromnumber3 {thrice repeated, and from number 8. Admitting StreevarySqrecttewalvarious,thsbenaty miesveryagreeableandvarious, ofwichfoundedonthesimplicity aloneofthe ‘Bumbersco notes. upon, +Sppiyingasecondtimethenumber5,weshallbe furnishedwiththethirdsofthefournewtones,A, E,B,Fs,whichwehavejustfound,weshallhave ttenotes,Cs,Gs,Ds,andB,oothatnowtheoctave incompletedofthe18tonesreceivedinmusic.Allthese tones derive their origin from thethree num- bers9,3,and6,multiplying 2byitself,asoftenas theociavesrequire;butwecarrythemultiplication of3onlytothethirdstage,andof5tothesecond. ‘Allthetonesofthefrstoclave arecontained inthefolowingtable,inwhichyouwilsehowthefunda- mental numbers, 2,3, and8,enter intothecomponi-onofthosewhichexpresstherelationofthesenotes,utor©[9,2,2,2,9,9,9,8 ../364]™Armmut#Cs [Zaaa5e.". >[400] 16 re" D [aia.9i9,3)3,3222cfasa]ge re@De[23355 0-222[la4so]12 som TE 2292935. |) ‘/4s0] 30 fF |o2290299,3,9 |Joi] 39fighiaasass. |{|540]98sol" G [23939933 °° {|s76| 36 sol#Gs|3)2)9)3,5,5.'. |!1/600]94 Ta“a[aoi9.3)919,3,5 52/o40} 40 sib,Bb13,3,3,55.".'. 22‘for! 35 sinBy[saaae nb2SSc/a)a atc”|aga9aa933 -‘708 48 1 orTHEmanPstcuonD. rr)Whilenote©makes384vibrations,thetoneCs great teothe mayaaaedby theircorresponding numbers:note¢millgive,then, inthe same time, double the number of‘vibrations markedby364,thatis768."Andforthefollowing ‘octaves, Youhave only tomuliiply these numbere by Biby4orby8.”Accordingly, notezwillivetwice "708, or1536 vibrations; note'r twice 1886, or3073vibrations; andnotetwice3072,or6144vibrations, Inorder tocomprehend the formation ofsounds bymeansoftheseumber3,3,and5,itmustbere- marked, thatthe points placed between thenumbers inthepreceding number signify that they aremalti- plied intoeach other; thus; taking thetone Fs,for Example, theexpression 225,536, signs 2tultipliedby9,thatproductby's,thatagainby3,thatagainby3,andWatby5.Now3bymake thatby3make12,thatby3make86,thatby3make 108,adthatby8make’640. Henceitisseenthat thedifferences between these tones are not equal‘amongthemeeives; butthatsomearegreater,andfibersleasThininwhatrelharmony requires,‘heinequality however. notbeingconsiderate, we commonly look onallthese differences asequal enominating theinterval from one note toanotherfemilonesandthustheoctaveisdividedInto19nem ones.” Many modern tusicians make them equal,{toughhisBecontrarytoheprincipeofharmony, becausenooneSithoFthirdisperfectlyexact,and theeffect ithesame asf these tones were notper- feetly intine. ‘They likewise admit, that werust .fiveupexactnessofaccord inorder toobtain the Sivantage ofequality ofsemitones, sothatthetrans-positionfromanyonetonewhatevertoanothermayWoorespectinjurethemelody."Theyacknowledge, however,thatthesamepieceplayedinthetoneG orahal-tone higher, that isCs,must considerably alfect itsnature. Itisevident, therefore, that infellsemitonesaenotequa,whateverfora rou.LI 50 or run puxasons rurve aaybemadebymoriciaetorenterthemsach; TechutetruebavZonyresisttheexecutionofade ign contradictory tote nature.” Sch, thea, theFennofthecele elyinany Eredered fro thenumbers 3,and Were we Farther tointrotuce number 7,hat ofthe Yones of‘ScarewoulbeJncesdantheartofme Earriedfothigherdegreeofperfection.Buthere fhemathematician giveswpthemosiciantothe Givection offs ext. 3aMay, 190. LETTER VIN. OfthePlearrederivedfrmfeMusi.Irinaquestionasimportant curious,whenceia ihataBopieceofaneexcwseatimentof Pleasure!Theleaneddferonthissubject.‘SomeBrig thatismerecapantaieleaue Producedbymusicisnotfoonded/onreason,because hatsgreetobengingtoaother Far From detiing thequestion, tisrenders only moreComplicated. ‘Theverypointtobedetermined isflowcomesitthatthesamepieceofmusicprodacestftcis vodiferent ince alladnit that nothingpenswithout reason” Others maintain thtthe Pisssure dered from fnemusic consate ththepeeEepionoftheorderwhichpervadesit.‘Thisopinion appeare atfrstnightsufficiently wellfounded, and tenis aore afenive.examinalion. Music pre- tents object oftwo kinda inwhich order iesSen- tia” ‘The one relates tothedierence ofthe sharp orfatfonesy andyouwilrecllect, that consits {enum ofaon pero byschnote Epthecame time.” "Thiscaferene, which speresLiblebetween thequickness ofthevibrations ofall bounds, iowhat iopropery ealled harmony. ‘he rowrovewon a steinpetmntwhhw sites aigoreote eerierata te agrostorthirdofthatof4108.Wocompreiond, BEG core netntaree, reae Senceeny ee encie Uoceciat eaten Merene‘rior,namely,tnomeasure,bywhich wotien{0 ini nee oe nee ars ee Eecces eaee ey eefey He iergedieme Hiei comm ers founded,hascertainlythemostperfectknowlere green rmenace 2 muusan pres roe rae ae vasionettpred,PortneLites spiesstpee titet thatthepereeptionaloneofalthepropostionsofa Piece ofmusic isinaufficient toproduce pleasure, Reise sabre as Facoeametean Saadseein ng ioe hme coeerent Geek date aentiee™ a yledge that occasions some trouble; whichSeriGrace recae Mitigen yore aiFSecrest onaoeStain microm eae meantfee mer rere Bien neaternea fia eta aae faresnn =maar epeepeersVencmomeur ou ‘theproportions, theveryplananddesign which the Tiutbconsttces thepeanareprocuredbyexqunte enedca lett Tiusicfoanearaccustomed torelishthebeautiesigs siemanne ee Bopioeennaieeeteredfn erie xeon iteteecageepeice tet eat wifawhichyoumaycoajecture,bytbegestureand iu Joyce ed ney more pe ree ‘COMPRESSION OFTHE AIR. cy imewith another excellent comparison. Whenfanguotthesense,anddacoverthattinperfolyexpressedinthe oftheenigms,youfel averysensible pleasureonmakingthediscovery; buiasipd andincongruous enigmts produce none, Such are,if|may'bepermittedtojudge,thetrue iplesonwhichdecisions respecting theexcel- Fenceofmunca compositions arefounded. ‘6thMay, 1760. LETTER IX. : Compression oftheAsr. ‘Tae explanation ofsound, which Ihave had thehhonourtopresenttoyourhighness,leadsme,for-‘ward toamore particular consideration ofair, ‘hich, being susceptible ofamovement ofvibration, ‘such asthat bywhich musical strings, bells, and other sonorous bodies are agitated, transmits the ‘concussion toour ears. It.wil beimmediately‘asked,whatisair!Foritdoesnotappearatfirst ‘ighttobeamaterialsubstance.Asweperceive ‘nosensible body init,surrounding space seems to ‘contain nomatter whatever. Wefeel nothing: wefeanwalk,andmoveeverylimbinit,withoutexpe-iencingtheslightestobstacle.But”youhaveonly tomove your hand brisklytobesensibleofsome esistance, andeventoperceiveastreamofwind itedbythatrapidmovement, "Nowthewindis othingelsebutairputinmotion;andseeingitis capableofproducingeffectss0surprising,howisit oseible todoubt that air isamaterialsubstance, ‘Indconsequently abodyForthetermsbodyand ‘matter aresynonymous.* stabtipcomaoedwandstomShrtatoostews Soseyaies,aeamBap t4|cxnrntenonoFTm1 isdividedintotwo utclasses,solidand nhlirettobreelameiet auldisainbord ihe cl of i os oer erg co fen aheeeintcheload Be,cmapbaz,eredOe sieOe ar te eee Toe rear oacsy diner ian, wean esas oatSoeSteee cee abs sea,oftg,compen,or,cuednto Haasree,Tedonagaued helon. igeprpeat is&teoFmea atthoendA'B,andopenat sigeAalent . troduced apiston P,filling weed ton SRS ein int wheih Seopangtepunovatemhenhae secomegotyilbrsberetieatde,Ege rain shed otSree eet, haley tenadhae reduced setineeartoad 1sStns.dieoraeeGo Repel crunedoethewilecntof seteomenntpceGinee foram soulinadoFserorm.‘rhesateLindoanececeSEARS as Fislasemaneg rienceseteypse mans COMPRESSION OF THE AIR. oS thenbenadnpaawae,whichwoulbeany ‘Drovebyotherexperiments. Henceitappearsthatiris&Buidsbetance,cpableofcompression,oriotherwornofbeingeaeed. 4smalspace;andinthisrespectitdifersentirerater.‘ForletthetabeA'BCDbefilledwiththie Tieig,ndattempttointroducethepion,you TrlSind‘itimpossible todrive.itforward.Employ forceyoutay,youwillgainnothing;the {abewillburstaoonertanyoueatreducetheater toaspace scnaibly smallcr, ‘This then iathex: sential diference between air and water: the later IS'sunceptible ofnocompression, butairmay boCompressed toanydegreeyouplease.‘Themore theiris compressed thedenser itbecomes: thos Bearwhchdecoied &ceran apace,whencom. Pressedorreducedtohalthatpace,becomestwice {idonao, ifreduced toaspace10timessmaller,it Isrendored 10tines more dense; and soon. Ihave Aiready remarked, that could itberendered 600 Eneaoredenn,woulthenbeadenaesarater,‘consequently asheavy;forweightincreases it tissameProportionasdont."Gathehearoettshatance wilhwhichweareacoainted inLikes Wwe themoat dense.” Itisfound byexperiment to eto times heavir than. water: 0that amass of sidatheormofwebaoeootwouldweigh 0times amasa ofwater ofthe same dimensions, Now euch amass ofwaver weigha 70pounds; the tans ofgold therefore would weigh 10mes 70, that ia,1850 pounds. Itfollows, that were itpost tible £9compress airtillitwere reduced toa space 10times 800, that in15,900 mes amae, itwouldBecomeandenseandasweightya9gold‘Batitisveryfarfrombeingpombetocarrythe |compression ofairtothatdegree,Youmayaifrat ‘without difficulty drive forward the piston, butthe Tratren«etdueanhemewrtne“Toa Sram me 86 anerAcrion an xLasmicrry fartheryouadvance,theresistancebecomesmoreswerfil; and before you areable toreduce thealrJoaspace10timessmaller,suchaforcemustbeemployedaswouldburstthetube,Unlessitwere‘ofuncommon strength. Andnotonlywouldsuchforee benecessary f0drive thepisian further, butAelforemondberegifokeepinthat state;forontheslightest relaxation ofthepower,thecompressed airwoulddriveibackward. "Themore compressed theairs, themore violent areitsffforstoexpand,andtorecoveritsnaturalstale.‘Thinnwa wocalheaping oticityoftho Air, ofwhich Ipropose towreat inmynext Letter. ‘auk May, 1760, ¢ : . LETTER Xx. Rarefaction andElasticity oftheAir, nave remarked,thatirisauidsbout800times amore’ thanwater;sontcouldwate,with. outbe (0vapour, ‘overa space‘somanytimesreser,andcould.{become of consequence a0 many times more sultile, ittonietSimilaronaiatencewiththeai-wbich ‘webreathe,"Butairhaa8propertywhichwaterthasnot,thatofsufferingcompressionintoasmaller space,andofbeingproportionaly condensed, axI jemoastrated inthe preceding letter. "And wedie- rer,inaranother propery nolomremarkable:iscapableofbeingexpandedoveragreaterspace, andthisrenderedsilmoresubtle."Thisopera? toginClotherarefactionofi. ouhaveonlytotake,asbefore,atubeABG Pe.3,atthebottomof 2>WHicn'A'C lettherebea,FE TRS Le fn introducing the piston ytasfarantoeKRbeair orranam® os tatrare wt! igo Loearene milehoSpertreDbecoelystopped.Ondmwtagback HOPESeeSEEagaeeeater gardTITAS diene dtengtonirlsspaceCFythesameairwhichwascontainedinthe Seental Pata Oakb a aad SoRfintw teinroeSmee HHUA lbnee et Ae a at ea a‘equallyexpandthroughthatspace,andconsequently reed elit hea eam hin cyer eee would you draw back thepiston; thewater would eee Sar een araSOTSEL hadrosa Si ae a chet ed ra maybe,itmakesunremitting effortsto‘extenditself ye ete caei eee aSaree ar at Su ele Sal pthc a ‘the density; inother words, the more the airisSeca t-tests a those efforts, Itwillbedemanded, perhaps, whythetirnowinmychamberdoesnotmakeitsescapeby (98 RARETACTION AND ELANTIOTTY OF THE AIR. thedoor,beingendowedwithanexpensiitycow alipltogecorypatra” tnswerirobviois,“Thuewoulinfalbly:happen, 424nottheexternalairmakeoqalefortoexfondfeltbattheefltisofthesrofthechamberto at and tat ofthe external airto.press iylageptheybaneeachtertdoman fateotres.” Pladtheexternal nraccidentally ne- {eedaponer dre” offey that re ‘stity,t would fnpare force faway into the gfmber wheetheai.ungcompreiod woud vie acre & of lasicy 1centwoldsecordinglyletflhyeliOf fhetnteral became equalfothatoftheexternalar ‘Andshouldthearofthechambersuddenbecomemoredeme,dieslygreetantatof {Beater woulfrelaayo; can iminishing,teastow dimaaitGocameequaltotheertertdairsthe current would then cease, snd the sarin the Ghame Ser woulbeinequimwiththeexternal.Free tr thensie n'a sate ofrest only when has the athe Gegree ofeaniity with that which surroundsHi'andSssoona8thatoftheonetractbecomestrore orleeslatte than theedjining, theequ rium eannolonger subsist; butte slat) natreater, thesrwill expand tse ‘and slide to Sires mhere {tis smaller: and from the motion fhe ar revallsthewindsHenceitcomestopase thatleyoftheaiiasometimegredier, sometimesTes,iathesmepace:andthisvritionieTnenedytheterathedeneionof whichmentspartcuarconsideration, TconfineInyoelt atpreset totees. qalitee ofai,iecom. ‘Lisetin ahdrorefeton enseatingyouvorecli finthemorecondeneed tm,thepester powerof fxpension ofelasietyitsegues:and“hat,om Eeony there ieed, hemorsie Guulty in diminished.” Experimental philosophers oxavere oF THE Asm. ry have invented one machine forrarefying sir,and another forcondonsing it:the former iscalled the ‘Sirpuonp, theliter thecondenser. "These machines Serve 10perform many curious experiments, with which you are already well acquainted. Ireserve Yomysoll, however, theliberty ofrecapitulatingsome ofthem, becatse they arenecessary toluce it’anaexpla thenatantproperties ofai,‘which, asthey powerfully contribute tothe pros:trvation ofanimals, andthe.production ofplants, respon ueheinipartance oforming autea of then. Mth Mey, 1760. LETTER XI. Grovity oftheAir. Inave endeavoured todemonstrate that the air ieald,endowed withhepaicalie propery offuifering comprossion intoasmallerspace,andof Sxpanding into 2greater, when noobstacle inter- owes, hisproperyor,ownbythenameof ing,oF elasticity fromitsFesemblance toaspring, ‘hichitrequires anefforttounbend, andwhichre: {uments form ans00na3theeffortcease,isaccom- idbyanother,imcommonfoiwialbody Erecerteamelygrevity orwig invitos whlchallbodiestondtowarésthecentreoftheearth, ZatywhictheyateUndertheseconofling dormsanespore.Toeearedereverymel vided,andveryuncertain,repo endmechanical couseofthispower;butityexst- fnce isindubitable. Daily experience evinces it Weknoweventhequantity ofitandcanmeasare |itexacty. "Fortheweightofabodyisnothingelsebattheomer which constrains ittodescends and astheweight ofevery body may beexactly meas- C enayrey ovrae am red,weknowperfectlywelltheeffectofgravity, thoughthecauseorthatInvisible powerwhichacts‘ponallbedi,forcingthemto"descent,maybeabsolutelyunknownow.follows,thatthemore matter utybody contains, the heavier itis. Gold EndIead areheavier than wood orfeethora, athoy Contain more matter inthesame bulk,ornthesame Extent"Botaoaitisaverysubtleandthinsub Stance,aditsgravityofconsequence veryie,thie riyusuallyeecepesoursenses.‘Experiments, Kowere,maybematecrateofproficng al convictionthtitponsoses gravity.Youhavescen Sowthoairaynratedinvemelor«tobe; sndbymeansofthesir-pump, thisrarefaction may becarriedfaraalmootentirelytoexhauatthe Bis,andtoeavethereceiversembly8vactum. Youmaymakeatbo ABCD, Fig.4,intowhich Fig.4.a ——Boasperfec totouch thefeiokaad iemarwerathetwosurfaces. ormtheexperi- mentwithmoreadvantage, lettherebealthebot. feoofhefe&iespre hough whichtheaemayccaafhepistoniposhforwardetaperartentecowelystopped,thtot&Rie oataybeincluded tebreen thepotEndthebottomofthetube.Havingmadethisrt Fangement, draw back thepiston’ andtheexternal firsnot belng abletofoes tswayintotetube,{herewillremainbetweenthebotionofthetbe andthepiston aperfect vacuum, which maybeine eaved itpleasre bycontinaing todruwGackthePiston, "You may thus exclude t€eircontained infveatel; andsuch vesot), reduced to' vacuum,being fredinaccurate seals, wilbefund toweighJessthanwhenfiledwithair.Hencewededusethisveryimportantconclosion tattheait'con * RAVETY OF THE Am. 61 {nedinanemptyveael®incresestsweight,and Ske DeWeese ele matinee Bateopinewept Sis ehsehr erred at SAG PP ey ean oi pat “Hst'ae ana nt Ss SP Me TS,Taitate speliale be'esaoe shel Seco ot eR ene, Sion, arnt ITfatonemirnce,tadagritthreine sacl “WoreSaania Patent SST eh OrSate eee oe fatal coum wou wetfofoes Soha Se Sag We TE runes eco! aco ti ‘Baghinthetral nateahnigravy SOR ears a Souter wef SSS La ee eatSpeealeeFoeetekaprs vail otheir iwhole massofairwhich isabove it.SHence it ies ipa ewe tpni |certaindegreeofcompression ordensity,whichig |eae pr heerr atat etna a cee ieatwilhceeelThceaaat Ceasetint Seoatata aewe Sete PSStyava |BEeeetolcaotache SPAIN ayeewotons Pet ei dBwee 63 oF THE ATMosruEAS AxD BAROMETER. 120subtile andsorarefied estobenolonger percep-fible.Wereyoutodescend,onthecontrary,into ‘averydeeppit,youwouldfindthedensityoftheait‘continually increasing, fromtheincreaseofthemass ofauprgsing downward yponit 17th May, 1700. LETTER XI. OftheAtmorphere, andtheBarometer. solmend fray|proceed emi,al gravity, rem thearthissurroundedonallsidesbythisGuid,and thatthespacewhichitfillsiscalledtheatmosphere. Itwould be.absolutely impossible for aperfect‘Yacuumtoexistonanypartoftheearth’ssurface;fortheairoftheadjoining regions, compressed by theweight ofthesuperior air,and making inceesant efforts todilate, would force itself into theemptyspaceandiit’Theatmosphere, therefore,occu jetthe whole region which surrounds theearth{heinferiorairiscontinually” compressed tythesghofthesuperioraianthattatthedegree Ofelasticity which results from thiscompression isbletoformanequilibrium tothecompressing power. ‘Then, although this airiscompressed only’ ina downward. direction, itproduces, invirtue’ ofita elasticity, efforts toexpand itself, notonly down- ‘wards,butsidewaysalso.Forthisreasan,the‘air in-achamberisasmuchcompressed astheexternal,which appeared aparadox tocertain philosophers:fortheyreasonedthus:Inachamber,theinferior airiacompressed only bythesmall quantity ofsu- Tera sricomprosudby theweightofthewhats airicom ‘weightofthewEinepery tiehighofwhchetmmene, "et .thedificultyisatonceremoved,bytheproperty ovrx srtoumas ato naoeran, 8 whichairpossesses ofexpanding itselfwhencom-pets riehe yrea deel riiets ance tae Rearrange at Porte Secs isteelas ea Seuerneay atttentyye Se en ep ae(tbrnanesAeGenteBicepy¢ attheendA,andhavingfilieditwithwater,or otherfluid,invertitsothattheoyie eee Sree ara eaeSkSeemsSeatertirate elSeaycoat artes Sau Someestoeioe ‘thetubewascloseattop,itwastheexternal air tube tobeplaced inareceiver, from which the airSaocrgereeroea stantlydescend. Theancients, towhomthisprop- Seu core Deere cia garnanne ‘todescend,theremustbeavacuumattheupperSorin eS ayet int sabe Seas asad inte ine wreath tment eerse Shoshana ms SESE ermae horror ofavacuom which thefluid suspendedErg yretamninessforceoftheairwhichsupportstheweightofthefuidinthetube;andasthisforcehasadeterminate morethan33feetinlength,waterwillnolonger{Sktgaoffuktheapaceatthetop wl,ofcour,boarealvactutl‘Theforceofthe ESS Ge pe Ls ee ‘sxpports thewholeatmospberit iconcioded thatbesebeingoqulwithacolumnofwater33feet itsheightcorresponds ‘tothepressureoftheatmo- iaeetceteec oar ae Sehepanonen bese tees iebaromeler fomtheMeghtoFtbemereury, which,asitrisesorfalls,indicatesthatthesensity Po eton are es Cee cc Often pnspe oir amababsammtarerar st oramoons, xe. 05 hichitiareducibleintoasmallerspaco,weare ‘habled toive anaccount ofseveral productions oftothnatureandart,shallbeginwithanexplana-tfon oftheerg, though Ihave nodoubt butYou farewell acquainted with that instrument. Itscon- ‘truction fesimilar tothatofthecommon gun butInsteadofpowder,weemploycondensedafttodae chargethe ballet "inorder tocomprehend theprocessofthisopera: tion,{tmustbeobservedthataircanbecompresvedonlybyaforceproportional 10thedegreeofcon-densatlon waich youwish toobtain; inthissate ft seentoextendiladteeforwhichtaken tre preciselyequaltotheforeonecessaryto totheaizewhichitactaallycouples.‘Themore, then,thattheairiscondensed,themoreviolentare itaeffortatodato;anditheaiiaraiseto'adene tity twice angreat aawhen its free, which isthe ane when weredice itohalf thespace which it ‘ceupies initsnatural state, theforee with which it fedeavours expand neal totheprewure of& column ofwater 35feet high. Figure toyourselt great cask ofthieheight filed with water; this fild will undoubtedly make astronger presaure onthebationoftheetalifyoumake'sholenit‘eurhebation,thewaterwlforcetalutwith ‘oasierable violence;andonstoppingtheaperture swithyournge,youwilbeabuanysensibleof thispressureofthewater.‘Thebottomofthecask sustdingthrooghout xaimilarpressure,”Nowaves- 321containingafttwiceasdenseasthatoftheatmo-{pheremostadenoprecanyucharesae;and Fitwerenotauficiently strongtosustainitywouldburst. ‘The sides, then, ofths vessel must beasStrongasthebottomofthecaakIhavementioned, In the same veesel the air were three times as deanaxcommon t,hereewithwhichIwoud ‘uponthesidesmistbeincreasedia 4 fonOfonemore,andwouldbethesumewhichis « oFaimeums, x70. srastainedbythebottomofacaskfullofwaterof feetin‘Youwilleulyconceivethatthis forcemustbeverygreat,andthatitmustgoonin-teasinginthesameratio,accordingtothedifferent Aegroesofcondensationoftheai.Thisbeinglaid ‘down,thereiaatthebottomoftheairgunacavity‘stronglyfortiedonallsides,intowhichtheairitImopeand morecompransed inorder toreduce it‘ashigh-adegreeofdensityastheforceensployed forthat parposecanadmit.“Theairconfinedinthis gavinailherebynequeaprodigiouspowerta forceitselfout;andif'anaperture1smade,Itwill fyofwithvelocityproportionalfothatpower. lowthereissuchanaperture,whichterminates inthecavityofthetubeintowhichtheballispot.TtIncloslystopped;tutwhenyouwihtodibchangs thepiece,youopen,foraninstant,thevalvewhic +hale1"dndheaerankingforth,forcenotthe ballwith llthevelocity which weremark inshoot. ing. "Every time you discharge thevalve isKept open only 4single moment; acertain quantity ofah,therefore,andnomore,canescape,andenoughstilwillremainforseveralshots,Butondscha {tsdensity and.corresponding elasticity diminishandforthisreason, thelatterdischarges areless forcible than theformer, tilltheforeeiatlength entirelyexhmusted. "Werethevalvetoremainopen ‘ny considerable time, more tir would make ite‘scape,whichwouldallgo10wasteforthisforcecisupontheballonlywhileitisithebarrelof iegiaysoonabehoficen saree fortheait.”Henceitappeare,1 ‘rereiposnbletocarythecondensation ofthis fluid agreat deal farther,youwouldproducefrom ‘thewind-gunthesameeffectsasfromtheguns and cannons incommon use.* “Alngunear nowcomarca eoanwhteoat gelUiiettngepterpnonatemenue Rat Sitges rosea epiedUelmaaae o‘Stoveraoameaan2 ow ‘RFPRCT OF KEAT AND COLD. Le ‘The ait ofely inscoring ondeon tgenceprivipie._"Cunpowder'sonyavobetzice Tired”Naturepredatorbeetnesaeoperiong ‘hichweemployforcompressing theaisutcaHoreca rate de“Si Teeth cenr at spent ia ue nt sZt ay wachinact“Thatafeoresfre,whichbatesopentheeliteenvelopestheerty tan nereie lc See ee ed he meee witness whee ars eee Seicleethewakerei pt ingen.reiaweveya tbctsprodacedfromthecondensationofawi ‘thissingledifference, thatintheoneitistheworkeresendeeetthaletreeos Mherefore inthis, asinevery thing else, how inf Soy te Spanier Nosan Sue pnd Beate? sy, LETTER XIV. ‘The vedbyHeatandColdonallNopargniecistshn aman thepropreleasmeno,ihas Perrotta a‘withatBodiemnotexceptingsuchaxaresolidE pmioserEE eens |Sees Seesees Eeeae ees ESSeas eeere poteGay era mn in owe pew cern gtReteatie ree aaate Ee Sies iterk ee Eis SR cco hae aty Seiemeinen2 Bonaamietae Hectares as Sires icin fe eaten tk fh oa coments bath raEcchanimntepose,fromachngeanonn-Seas imi tercape1caseofthepyrometer, whichIhavejustmen- considerable space,ontheslightest changeproducedfeist ear EEE eatin etter thatthebarisbecomingfonger;andantheheat irene ams atria at a .eee ee eee ira estatih, er cremmeeea hortentthe clockgooefaster.Nowitiaremarkd, meaary doemarcetuat Boop "ES ers git, Oesydifersgreatlyaccordingtothonatureofthe “ON ALL Bovixs. o tabstance ofwhichtheyarecomposed. Infivida,Seehtaie intakeeglanewheBGPeee fetho glialtaalMig ateianthet fo.“OnheatingtheballA,theliquorwill too.fromMtowardsC;whenitbecomes™ Sieta Teteitaecease | ‘Thisclearlyproveshatthesameliquidocx cipesegenre eater sensmallerwhencoll.I.islikewiseclea,thatMaavtratee ooormentoereaia tnaeopeemaaereemeer eeeosmaseratm, gota!ii octane Sat nce pet rll cosopyintie acs tenant Preprton iea" aera intra mentthenisSzceedingly ‘propertoindicatetous healt See SPPraMent tate 038 Iter me Tas tok tna rake et ia nea omaga ate‘mentiscalledthethermometer,* whichpoints out “Steam otmsrar eee id SERRE Sereneated Seine aratecoeDemategpawatk SS 0 cons rnopeceD otTm ‘hechanges thet take place inthetemperature oftheair,andofthebodiesthatsurroundus.Itmust not beconfounded with theBerometer, whose ‘use Isto indicate thegravityoftheair,oFFatherthe fOorcewithwhichitiscompressed. Thiscantion isthe more necessary, that thebarometer andthermon-lerhaveacofisiderable resemblance: beingbothflactubesfiedwithmercury;buttheirconstruc. {ion andtheprinciples onwhich they arefounded areentirely diferent. ‘This qualityofbodiee,ex- tensionbyheatandcontractionbycold,belongs Tikewiseinaverysuperiordegreetoair.‘I ‘explainitatgreaterlengthinmynextLetter. Teh Mey, 1700. LETTER XV. ChangesproducedintheAtmosphere byHeetandCold.- Haarandcoldproducethesameeffectonairas+ oneveryotherbody.Airisrarefedbyheat,and condensedbycold.FromwhatIhave‘aidofthe slaniityofi,youenpereiveThatacertain ‘quantityofthis’Buidisnot.determined to nlyacertainspace,analothrbodiesare;butby intrehanperpetualtendencytodilate,and scullydoenexpandTel,alongasitmeetsno ‘Thispropertyofairisdenominated elasticity. ‘Whenthshuisconfinedinyeeitmakesoffortsinevery directiontoburtit;ndtheeeffortsHence wecometothinconclusion, thttheelas: ‘icityofirisinexactproportiontoitsdensity;»0dose.aye Rome.ThesaecommonsthersetneecommasoneUnieBaesongsTr Stalsonracnpoye!arpabmepe pene arwourames by uEAT AND COLD. TE thatwhenitdensityiadouble,itselanicityisUke. ‘winedoubled; adthat,ingencral, acertaindegree ofelasticitycorresponds toaproportional degree ofdeamty”XbabeemazkeHowever,thai eeplacenolongerthanwhiletheairpreservesthenamedegreeafheat"WheneveriThecomen itacquiresgreaterpowerofexpansionthan whatcorresponded toitsdensity;andcoldproduces theopposite effect, bydiminishing itsexpansivepower.Inorderthentodeterminetheelasticityof massofar,itisnotsuicienttoknowitedensity Youmustlikewiseknowitsdegreeofheat.Ya ‘rdertovotthisinaclearlight,letussupposetwo‘chamberscloselyshutonallsides,butunitedbyadoorofcommunication: andthattheheatinbothisequal. Inorder tothis the sirinboth chambere must have thesame. degree ofdensity. Forweretheairmoredense,andconsequently moreelastic,intheonethanintheother,partofitwouldescapefrom the one, and force its.way into the other, tlthedensityinbothwerethesame.Butletussup-posethatoneofthechambershasbecomehotter{hanthether,tharthereby acquiring greaterclasticity,wouldofcourseforceitselfintotheother, todediethatwhichifound,heeintoasmaler i‘inbothchamberswas brought othesamedegree:“purge changethereel be acurrentofairthroughthedoor,fromthecham- ber whichismoreintothatwhichis,lessheated; sodwhen theequilibrium isrestored, theairwillbe tore rarefied inthe warm apartment, and more Condensed inthecold; andyettheelasticityofboth ‘willbe the samo. From this itelealy folows, that Fro masees ofsirofdifferent densities may have thesame elasticity, when theoneishotter than the Sonittnayhppeo hatiththeoumedegreeof on,itma atwiththe.same density,thoymaybeendowedwithdiferentdogroas ofelasticity. | ‘72 CHANGES PRODUCED BY HEAT AND COLD.fethettneregitcrarsatbearerSrtirncrar tearm gat |Seas end SA enh cere SpieraireSemin havens mabesirarm Hieiee yer erat happenthattherewerenowindoverthewholesur- pepe yeege rea meaoe thisnever happens, there must ofnecessity alwaysSesMihomeneaoa Ponanseanware Seredeenumerate lessviolentwindsare.Windsarehardlypereep- Fossiltodoubthatconadrale levations singe.Behrman ieeeprevailsallovertheearththesamedegree SitaGeaehero Greif alee errsSEReaaoes dana Spon tact leanee ofheatthererustbealwaysthesome:whichisa oieareeeaeeeeee Toofheatandold’whichwefeeonthosur. faceoftheearth,duringthecourseofayear,and gygnotoneday;withouttakingintotheseeaantthe diierence ofclimate, thatis,theintolerable heats coup veut oN ios wouxtams. 78 feltundertheequator,andthedreadfulcoldwhichConstantly prevas towards thepoles oftheearth Experience itself, however, confirms thetruth of aE astoniohing fact.” "The snow and iceremainequally,cunmeyaodwinter,onthemouatsineof SUiigShand;andareequallyunchangeableonthe ira yan PeraSana edr eryequator,andwherethere reigns, revereacoldexcennve ahaoftheplat ons,Theheightofthesemountains 43Eng Temes, or24000 feet,Fromthieittaybewithconfidence Concluded, thatwereitpossibleTbrusoascendtotheheightof24000feltaboveSecarywesoul ayemestitheae ofca Ziadeacesaively severs: WEshould remark therenosensible diference dar.ingeithersummerorwicteruntertheequator,oFTer thepoles. "Attisheight andstil hugher, the ato ofthe stmosphere is"univeraly,andatall feasous, the same’vand the variations ofheat and foldtakeplace nearthesurface oftheearth alone,{tisonly fnthee inferior regions thattheeect oftharayeoftheaunbeconesperceptible, Youhave, idoubtedly, somecuriosity toknowthereasonofthisTestabethesubjectofthefollowingLetter.SiaMay,170. ‘LETTERXvI. TheColdfit‘ighMountainsondatgreatDeis’ FatomhighMounts7mgreatDepths’ Ih very: thatweshouldfeelthe simsBogreeofcold’inafregion,afterwehareHenttcertaineight,ay2,000fet:conse,esky niyocisebtinthesee SeanerentsolsoFteaaaeae vou “1” COLD FELT ONHIGH MOUNTAINS .*‘Thisvariety, whichtakesplaceatthe SER ete acd sine‘hesun,Ttappearsatfistsight,thathisiniuenc® Turbethesumeaboveand below,especially when eet hn wet ofm0 eh wee Eos ee ntef ye._comptred tothedistanceofthewun,whichiabai nar fey"rere talc which itedDealesFortspune{beginwithremaring, Bareagofhobintmeteheat Syabeeosaunheepage hlsRecah headacorobjets arodenominated anor, se ®SetinOgee eye:diamond,wast,ealsevereotherfaa,thoughsomearemoreorlesstransparent than Siete "Sar otase ratte fouls Sang SetittnteRellchs eek-Bodynottransparent, anwood,iron,Bc.Bodiessathotomttihiahsd gore.teat Baselyatlceoh fun,setaonfireopaquebodies,whilethegasitselfSET ch ai ceed fone becomes somewhat warm,onlybecause itisnot apeeaeaeee thstid,bing opaquetuiheviedbyte apaucyene picesSota odycommunicates thatheattoalladjoiningbodies; thewateraccordingly derivesheatfromthebottom. ‘Afthewaterbeverydeep,sothattherayscannotspecgcvw eteSSfe SS renee oe ‘abieTsSetdecigs ccd8tet Ghenrimare eee fim twprep ‘ioaghthesanbearsuponiPeattesttyoop IhighordegreethanrlaseoFwater,tfllowathatit ulesSreeare seinen agrees ferris irae Soraraeee Aerlear acaae ieiia as {nitstemperate bytheraysofthesun:exposedTeompharesnotpefeciytacopretHsoveEe no oatSeerseysmearaivetsoly IASieeemeeeee eaeof34,00focaodboyoR,theais9a ‘ileand#0pure,thatitis lytransparent;and Pelee Seymore a Ebcosydeena Serres Seca denne TonlePacietacrest uponsuchasareadjacent. Henceyouwilleasily ‘perceive thattheraysofthesuncannotproduceBratcha'stytaca HoesheatiacaaeeaeetShea e{nochrionathe”asnoinfra’there,Sheserncaaeaeeet Sno eeee ‘TheityofQuito,inperisalmost,underthemime cores 70 cou veut onmom xovwrum sbendanty temperate, and dere very lite fomthatofParis, "Guitoissituated atgreat height feel uaeotesartng FaeseeahatecandforSeveral Foe eeteetanaunectioncolts ERorrer penta ugh snaDroste wlmhhree Caer i iaatnest at alors tea otRearenercaltenhorareoeeSeePierhaitincontgusar onalsides TopeticeofwhichNeapeofthesueft ‘Treotfection fesollandnosolutioncanbogiven but this :—ThattheairofQuito,beingveryelevated, ‘mustbemuchmoresubtile, andoflessgravitythan IrsudfhebomenehayeSane considerablylower,incontestably proves Trthts ofestaSoonertt,itunconelsrpeadhere gothere tndnelnowbyexponenesirensmacsessedrmponowy sep oea”net he FetterSenseIsesurpngrypps,andlowerstill,ifitwerestillpossible See acreotateeeSeaaeTera erin etney hepasreapon® RYRearhanenedseeinnguanesseeon theoraoftheertendstenowwhiehthoy‘eectstverygreatdepthipmosttmpercepibe,2thingholdsreepeeting considerable Thceamctingtons iSane180Teen nett2rrrmtrntgfnfaebronia) ‘ or utr ” warrenxv, OfLehndeSportslanepokeothoyefesnwhichwo fermepar tmme sin eee E=Pyle,aoonieenterofpheieesa malohavetakenlilleinterestinthesolutionoft.‘They. herecrnaatereeintyendowed with thequality ofshining, ofgiving heatSeren an,vonagereeisteDahgvorwidefe tions,inconeeivably small,ofthesunhissell,oFof ety ok mec wieeanenGraeee Tecsives! thoughnopartofthesuofthe aoeuedhtereewesote Folocanntateeter pat) ene a Ten aiePeet oped lobules,whichheallsthesecondelementhesop Posesthatthesumisinastatoofcontinualagitation, ‘whichhetransmits tothese globules, andpretendsSeeamass astie |famgeerezirne armornsee |Reeder icme deet ‘Desceries,whichlabouredbesidesunderotherdilBerar ieee REE caintnoe ‘4 7” oruoxt—sverams oF1ndmaintainedthattheInminonsraye arealyseparatedfomtbebodyofthe'oun,andtheFartlesofghthenceenuewiththtticoncety- BievelocSichbringthemSowntusiaboutSait misutge "This opaion, which isthatofmost modern philosophers, particularly theEnglish, is fale een ofcha, gin SEayeecnncleorthocusandotetanaoeebiatevasopageomou ireconclabletoFeason,"Forwerethesunemiting Slonnualy,andinalirectoge,euchfoodsOf fuinousmienwithavelocitysoprosigioun,hemust clipeis oroutndesron fonsherthotapesofcanyagespres This,however,iscontradicted byobservation. It Cannotbe'nmaterofdou,thatafountainwhich Should emit steamsofwaterinaldirectionswoud Rexhmantollaproporiontthevelocnyofthe Spiccion{ouchoretoewangheeraysoxaed Shivaveloc ooconceal” Lettheperiles +Sich ayy oflight aeformed besoppowed Stem ouplese,nothing wilberede Watinned‘hatTleemanationinpotfea1all ‘Suvisvistle,whichprovesIncontestaythet’fd femeerpostohenreedove potwhichJouoccupy."Tnecasefsverydiffrent ‘fomthatoffount, whichshould emittres otwaterindecoy ForomPtinthefountaincouldfarnish‘onlyonestreamrecteddtoe- Estemitanninenumber ditveingtnemeclvessateetgan Thycrete owefail Increunceteexpenseoflulacusmater,whe ‘Senotherfeuty,andwhich inohmsmeni,ndichereely DRICARTED AND NEWTON. ” quality,ananeverywherefaayeofthesmst tyandaseverywhere terays ofthesammist Sercromtingtheraysofthestars,theicollisionmust sevilenttheekteme.Howmoshadestin hangedbyeachcollision’ ‘Thiscollision.mtakeplacewithrespecttalluminousbodiesvn atthesemetime. Each,bowever,appearditinetly, withouteuferingthelightestdorangemen rom27Biherscerain proofthtmanyryemayaan {throughthesamepointwithoutdisturbingeachother, whichseemsirreconcilable tothesystemofemana” tion."Lettwofountains besetaplaying uponeach otherandyouwilimmediately perceive theder ent stream diaturbed and confounded: itmust of consequence beconcluded, that themotion ofthe "ayeoflightiveryesenally diferent fomthat OfaJet deau and ingeneral from ‘allsubatances ont er parentbodieshich ferelytraamitediaarecon ‘supportersofthisaystemareundertheneces ofatingthattherebodiesconfainpore,disposed {nstraight lines, which issue from every pointofthe forcetracediaaldirection1bingnone “ceivablehowtherecouldbeanylinethroughwhich ‘aray ofthesun might betransmitted with such, Amazing velocity, and even without the. slightestcollision."Herethenarebodieswonderfully porous, ‘hich have theappearance nevertheless ofbeing extremely solid, : Final inovdertoojoy.vision,Uiraysmustaquetint theeyeanpancho abelaace ih the same ‘velocity. Allthese dificullies taken, together will,Idoubt not,sufficiently convince you |thatthesystemofemadationhastnnorespecta |foundation innature: and. you wil certainly be astonished that itcould have been ‘conceived by20greataman;andembraced bysomanyenlightened,‘philosgpbers... HutitilongainceCiceroremarked 8¢©pameourms artexomo Tu{haothngnomadcanbeimaginedsffdno fupportertmnongphilosophers Forwyownpars, Phouleathiosopler toadoptthopinionin " ‘Ith Fune, 1700. LETTER Xxvun. DiffeliestendingthSystemofEmancivon. Howsvm strange thedoctrine ofthecelebraied : [Neston may appear, thet Taye proceed from theran iy's continual emanation, ha, however, been v0 {eneraly received thatitrequires aneffort ofcoa-[SpeoainGuan,"WhathoneyCon,‘tributedtothisis,no.doubt,thehighreputation of . thegreat English philosopher, who iat discovered : {heSuclant themotion ofthe heavenly bodies;fitwagthisverydiecoverywhichledhin0thersernofomneserat inore10,ago hishecry, wasserhenbanly fing whole tactoeHeavenswithasullemater,roughwichalltheCelestial bodies move atperiect liberty. ButitisralKnown,thaSodymovesairmustmeetWith acertain degree ofresistance; fom which Nacton conclodeds that However subtle the matter Cfthebeavens may besupposed theplane mst counter some refstance't their mouooe., Bu, said he,thismotion isnotsubject toanyresistance? {he imévenee space ofthe heevens, tertore, con: fainano matter Aperfect vacuumthenuniversally alls.‘Thissoneoftheloadingdoctrinesofthe Rlewtanian philosophy, that theimmensity ofthe pledbybeheavenlydies.‘Thisbeingaddown, renbodiesThisben Trefobeweenthswunanduyoratlatfomthe sundowntotheatmosphere oftheearth,anabso. \ sureoFNATION. a Jutevacuum.Intruththeartherweascend,the toore subilewofindtheaistobe;fromwhence ‘wouldapparentlyfollowthatatleagththeairwould beentirelylost.Ifthe’spacebetweenthewunand theearthbeanabsolute vacuum, itisinopossitle that‘theraysshouldreachusinthewayOfcom.runication aethesoundofabellistranwoittedty imeane ofthe air. “For ifthe air intervenig be.ffreenthebellandourearweretobeannihilated,‘weshouldabsolutelyhearnothing,letthebellbe"Hivingptblahedihen, aperfect beaving perfect vacuum be,seanhefeveytieteecemane 0ote iniontoteadoptedbutthatofemanation;whic Si umingun bolicemitfayewhichareaeage Betieemitrayswhicharea fastenelyaaofttanadatedom rigeredfore.muabesuchog ve ibordert0impressoarayso Heit‘thatinconceivablevelocitywithwhichthey fanromtesuntwsinthepaceoightmae SieDtltunnoewheterthetnobeca EstatwthNewlendingdoctrinewi anabsolute vacuum inthe heavens, ihattheplanets ‘ay encounternomannerofresistancetotheirm0 Hons"Youu conlaeonamomentseacuon, paceinwhichthheavenlybodiesreyave, InsteadoFemaiag4racist beiowith therays, notonly ofthe sun, batLikewise ofall ty otherstarswhicharecontinalypassingthroughit fromeveryquarter,andinallrections, within- crediie rapidity. ‘Theheavenly bodieswhichtrav-‘ivethesespaces,innteadofencountering avacuum,‘oil meet with fiemattor ofluminous rays in'& Tersbip agitation, which must disturb these bodiesindetonsfashmoetaniworenae |eee an Thus Newton,apprehensive lestasubtilematter, suchasDescorigs'hnagined, shoulddisturbthemo: C) surrexoFmuxaiox.tionsoftheplanets,ndrecoursetosverystrange tpoticatabdquitecontradictory tohisOwnines ‘Som, a,onhishypothesis the planets must beex- Pa erate ely orecoer ave ready submitted toyowsever! ether iam erable objections tothesystemofemanation;and haremsnhtirindinedthe tlyremonwhichcoudinluceNetotoadopti, fifoselfcontradictory axwholly to"overturn i ‘Au these considerations United, aveusnoroom Aobentate abouttherejection ofthiswrange system oftheemanation oflight,however respectable the . Stthorty ofthe pilosgper who invented te ‘Newton was without doubt one ofthe greatestusesthateverexisted. Hisprofoundknow- Frage,andhisacutepenetration intothemoetfid- dou rhyeterie ofuature wil beajust object of . Stnaration tothepresent tndtoevery futvo tge . Buttheerrorsofthisgreatmanshouldserve,toStanding? which,sterhavingwaretothegress whiing etForiegn angerofngoginfomaa contradetion. ieeenh woatneonandineesintencia sohamiiating,nourresearchesnfthephenomena ofthisvisibleworld,whichliesopen.totheexamina- falGo!Tetutourselveswithrenpeettotha, efunfoourscivewi th Invisible and which concern our eternal ealvatog?Onthisimportantarclearevelationwesabsolutely canny foun; ainweoohforall orev Oieithitprotoveneration.When Presents0uethingywhichayappearinconcetr Sieisevebateelietaperectonof amanunderstanding,whichiea0apttobemisled, trennoenueject,"Whenever heart .Drotended freethinkerinveighing againstthetruth Errelgion, and even ancering atifwith the most eaulicieney, Leytomyeel,PoorWeak ew svevex nesrscrmo tient. 88 ‘mortal, how inexpressibly more noble and sublime Bethe subjects which You treat solightly. than those respecting which the great Newton was 80 yma coltwhyourhighnessfo fecopiaefectovenemembtanee}‘ccsions00hFane,1760. eanently LETTER XIX. AdiferentSystemreppctngtheNatureofRaysandofLight, propre. «cauBaretoonathyamfeemanation 0Taye of ryunder insuperablegute2fateeckoavacua forthe .ce insequallyuntenableax |HetoPigiwouldcomply aiitwoRage tty,ustbe.adit fryth,once through ‘which theheavenly bodies move is Aled wrth asbtile matter; secondly, rays are not an Zeta emanation fromthe sun Sod other luminous otis, invirtue ofwhich part oftheir eubatance ie olay emied fomthem,scoring ttheoeTineofNewton"ThateubilematterwhichfilsthewholespaceinwhichtheheavenlyUodiesrevolveiscalledether. DOritsextreme subtlynodoubtcanbeentertained. Iorder toform anidea ofi,we have only 10attendtothenatureofair,which,thoughextremely sabie, even onthe surface oftheearth, becomestuoreendmoreoa8weascend;andentirelyCees,iTTimayusetheexpression,whencomesfobelat |,tn'thetuber.‘Theetherthen,isLcewiseaidaxtheairis,butincomparably finerandmoresubtile, sweareanurodthattheheavenlybodiosrevolvefreely through it,without meeting anyperceptible ew evernu ansprorixo THE resistance, Itisalso,withoutdoubt,possessedofEestibymeasofwhichhawtendencyfo xpdTelaaections,andfopenetratelato Steewhere there wold oherwite Fesacai: tat iby some accident theether were forced futofanyspace. thesurrounding fll would n-stanlyruthfnandflitagain.Tevieoflelacly heetheritobefoundaotonlyithe reine whesveonestn crebutitpenetratesthealmosphere universally, Baines tetbytheporeofalbodesandpases _ lien aly apore llodis adpees ofthespam foexhat theaHomteclen ou mustnotimaginethatyouhaveproducedaii Rbsoluteacum;fortheetherforcingelthrough , ihepores oftheteceiver, completly fils itinan instant Having ‘filed’ glase tube’ ofthe:proper engwithmercy,ndmmeraed1whenfo Tightbesopposltetthepartofthefaewel Kemi attheparofwhi ishigher‘thanthemercuryisavacuum,becausethe Aitcompletly exci acannot penetrate {heporesofglass,butthisvacuum, whichis appe- renonly,inundoubtedly suppliedbythether,in- ‘nating self without thesmallest Aieulty- Tein bythis sobtity and clastiity ofether thatI shallby-and-by explain toyouthefemarkable phe-fomenaoflactic.” Ittsevenhighlyprobable thatetherbasanelatiitymuchsuperiortothatof aandhatmayofthphenome ofnairere producedbymeansofiFormyownpart,1have Bodoubtthatthecompressionoftheairin powderistheeffectoftheelasticpowerofether. Kat asweknow byexperiment tht theatin itis bndensed almost 1000 times more than common aatthtee clnty ewan:1sgrater,theelastictyofthe. EReSFisocantconadoehly 000eaal* areasoFtao. tortanthaofcommonat*_Wosalhen Fiveaustideofther,inconsideringitanafuldiRmanrenesiraiitn, Sather hncomparty morestl,andBows“ifevingeenthenhttheabythenveryql siniropeetoforacinganogons orShaking oftonoowsbodiesandadifthem iFcectanwetdinhgromeationof ‘sound,itiaverynaturaltosupposethatethermayihe samo crcumatance amine recive ateionsinthesamemanne,toanatem1hePessttanet nianyfh rendwhawilotheefithoesofter] Yerwilindiagossaonce,ieap poatenuhnatch EihtwiTaintheryeofligtareavthng leatthe c tigi aesthakingsorvibrationstransmitted bytheether,ws soundconsistsintheshakingsorvibrationstrans- “Thewt,then,lotesnothingofhismbstanein rhean ten seco,aymoretaeablinranglo ‘ovingtayo,hereisoTosen1emre- SeUREtlaofhnaholdeveruray ‘Sono, Wat{havosudofthewonmsttno Sevetntedolfiomioosbaieachfret. wl vooatedlybeobjectedhatthoneres. fal aminaen‘ersty rt and th aneShyearlyfolpo,heyal tpeely extngie tat. =‘Bastintimebewanedaway,andthatthepealmeintnoet ma Se | SSeS easee tr Baie Tink 86 ew avereg nnascrme ton fsainnoacerte,Butitntobe. Ghd Meee hen bondesterlghistirow outenake, stage clheise vocmace ‘romtheaynightNow Skeandexhalationevidentlyoccasion«consi tratetonwhchmanfosingeda {fomtheamokeandotherexhalation, tbeTuminousflydoeswealcccionnoapenare "Hierayapymemofrbferednou, GSjeu'Ln!pohseentatwatay atin of eatwtance, whch proves hat gtSinepdsnowolintodin {hough theeumiuminates tewholeworldbyhisreeecong”ofhsonsbeane®ie Tightbeingonlythoeffectofcertainagitation, oFeat cntont ofhs mi enc‘municated totheadjoiningether,andthencetrans-tleialdrecownbearoftutte ‘etdats’ blickcommu SERN cen ngtaon te cremantn $store ee tn pra betwee aonfonnnytipeila Contre outerandjmsbyexperiences Sorento ore weap roel hePa’ Tomenuofpiretohespremofemanationie ioediicieeweecon? Ti oe" inTentans reesetitapeemaier eeamrameste Siiaaaar sskeeneoeete Sevmacom usrcee ieeeSSeSesse moeee maorAcaTion oF WoHT. er LETTER XX. OFthePropagationofLight. Teionoflightintheetheris ingmaneSiltotltofsoundintheir Justanthovibrationsoccasioned intheparticlesof air constitute sound, inlike manner the vibration OFthoparticles ofsther.consisghtorhum omerapes0inAgengoeStoai ‘onorconcusrion of lesofether, which isseeti agee get‘btdty, invirteofwhichitpenetratesllbodies Tucksfete,however, citytherayofligt inmany different transmitting ortbepropagationoftheconcussions, O¢thieaha fretafgetahevon1confineyaaat Presenttothepropagationofraysintheetheritself, ‘wichfllthemmessespaceinwhichtheheavenly Todieerevolve, ‘Therethepropagation takesplace Saporfect erty. ‘Thefrsttingwhichherepre-sentaitselftothemindistheprodigious velocitytheraysoflight,whichiabout800000tines ‘more. rapid ‘ofsound, though this ‘travelsnolessthan1100feetin&second. “Thisamazingvelocitywouldbesuicientofitself tooverturnthesystemofemanation; butinthatwhichHamstompingtoestabaiiynatural consequence, fromtheprincipleslaiddown,a8 Hopetodemonstrate. ‘Theyarthesumewithose‘onwhichisfoundedthepropagation ofsoundinthe‘ir;andthisdependsatonceonitsdensityandelas- ticity. Itisevident, that ifthedensity ofairwere|dlmthisnd,soundwouldbeacclrated andifthe lawoftheatweeincreaodthesamething ‘wouldhappen.Ifthedensityoftheairdiminished, ‘ind itaelasticity increased atonce, wesbould have ry RorsoaTionoFLiou, ‘8twofoldreasonfortheincreaseofthevelocity ofsound.Letusconceive,then,thedensityofthe tirdiminished,anditselasticityincreased,tllite sonytdeltiityDocumeegaliothoweofether, ‘andweshouldthennolongerbesurprisedthatthe |velocity ofsoundhadbecome manythousands oftimes ‘thanitactuallyis.Foryouwillbe toremember,thataccording10thefirst ‘woformedofether,thisuidmustbeincon- cceivablyrarerandmoreelasticthanair.Nowboth ofthesequalitiesequallycontribate toaccelerate {hevelocityofvibrations.Fromthisexplanation, iheJetsrecyofghwornpe ‘anythingirreconcilable toreason,that.it FetherperectlyHarmoninn withthepracpenin Gown;‘andtheparallelbetweenlightandeoundis fnthisrespectsofirmlyestablished,thatwemay confident osintainythatifairshouldbecomeat ‘ubtileandaselasticasether,thevelocityofsound ‘woaldbecomearapidusthaloflight "Thesubuiltyofether,then,anditegrostelas- ky,aethelretonwhichweamgforthpro. Agiusvelocityofthemotionoflight;andwolong ‘a8theetherpreservesthissamedegreeofsubtiltyfadelasticity,thisvelocitymustcontinuethesame.‘Nowitcannotbedoubtedthattheetherhas,throughthewholeuniverse,thesamesubtiltyandthesameclasticty. "Forweretheetherleeselasticinonelacethaninanother,itwouldforceitselfinto.it‘Ellthe equilibrium was perfectly restored. ‘Thelightofthestars,therefore, moveswithasgrestvelocityasthatoftheoun;andasthestareareat‘Amuohgreaterdistancefromusthanthesun,amuchgreater quantityoftimeisrequisitefotranamattheir Tays tous. However great thedistanceoftheun ‘ay Appear, whose rays, nevertheless, reach theSurfaceofourglobeineightminute,shexedstar nearesttousisatleast400,000timesmoredistant ‘hantheoun;«rayoflightissuingfromthatstar raorseanonoF10H. w willemploythen400,000timeseightmutesin Tove©uth8houor2305Saye, crac yearenetny. lethenupraie ofsxyarsncheayeof light ieouod fomthat xed star, theTeast rota, 28bay temoatrani nerovenTetonsierabe toytroupthesecede Be toAythroughtheapacewhicepeeFatesuofromthatstar.WereGodjustnowto‘reteenowhuedetresamedatas,could Setbesnneibleowllmorehanpersad Speedsoi rays Fegure timeto fatethisdstance,HadonebeenSreaindattheSoptaningoftheword‘thousandtimesmoredie: ‘tant than that which Ihave mentioned, itcould not yetbevisibletous,howeverbrilliant,as6000years Eimotyetlapaedsincethecreation,Theetasher ofthe court ofBrunswick,Mr.Jerusalem, Eoshapplyintroducedthisthoughtinoneofhis sermons,Thopassageransios— CEa sthwhichyou ‘inhabit, toallthebodies ofthevast universe, which Soo farabove you; iam into theimmensity ofSacgwhiehlerasespeovonythetowsratcteBich"youreyeoareabletodiscover,andthee ‘Shoveight,omthemoment ofcreation tillnow, Teenntyoflingo ofGosJotithisrepre: rmenaty0 eaotGodjutsthisrepre:sentation.” (Sermon ontheHeavens, and Eternal Beatitude.)STfattgomyselt thattheereflectionswilexcitea detiroofartner ivtrution respecting the#ystem, ofighromwhichderivedthetheyofcolourmattisoa,TihJaney1700. ae Ld (OMTHEDivrANcES OF DrainteDisofnyoa iae a ‘Treobservations whichIhavebeenmakingre- ting thetime which thelight ofthestarsem- Hoyemakingprogzemowntoonconrey+ jingideaoftheextentandgreatness ofthetini- etisalatie Pte User aesodoBaglinmienWhatastonishing vesity!Yetthenearestfixed segateatiheae Seon ea fetsantaaach et Sciromthatstarfobeconveyedtooneae wouldrequireaperiodof5,400,000yearstoreach SOSteed ones ek &den iatee aneanBetas eeeri eeak Tayeofthea ouibly reachta.How Bideea aritere aa Sootheeats geeSeaycarengeennaFindaenim 2 sw mires ome at solar opery atWere, then,oneofthesestarstobejustnowan-Ness taeeetter walesgiesScreamPee or FecesSatyoewong stedeyorseek ieeesoit gee Feeley actaidelaas acerca it ieee dom; andthat themore knowledge weacquire on Pees pore Satya aernanraneseinieat ontshia et mataPe oO erate ee eabesokedsinthefirstplace,mihercinconsistthe:‘pipiens hetattecca Si, eae “haat Baie chee cae ae and this, bycommunicating itself tothe circum- schema ities tha Soci dee Gane aessale iTegeprtteenlt sie tts et nt SERSRRTC RSs Ae 0seancosusmtiremsneem ticlesofthesunmust be inthis Samciingirakee Sha ienechiwile gt sre ceparhporeBerchet mashdonsatingon Sarg,aetycosetsfonEeeeleet aaaekagleLaer zie oteEM onc onasacta neSpear rgsyeneniacinSoS Tee es foendcarenonealprofhone sargeraeieatoleioon fon Esalace|Wireeh BEashehepehenenwsgetee fomofeok,eyputTomoareseeegreyAaeheae SPcv goon spacingseecthepooreect ahepateetnhgi eg‘Dataneninglnatent seekpanama tecomot Horie omiernceofmanyarogisfiedifourideasarenotinvolved incontradiction.hood | aarvas oF Lummous noone. 9B. LETTER XXII. Biucidatons omtheNatureofIaaminowsBodies,and‘theirDifferencefromOperBodiesWhamined.‘Taxsunbeingaluminousbody,whoseraysare‘universally diffusedinalldirections, youcannolongerbeat«losetoaccountforthiswonderfulphe-nomenon, Whichconsistsintheshakingorvibrationwithwhichalltheparticlesofthesunareagitated.‘Theparallelofabellendsconsiderable assistance towardstheexplanationofthisfact.Butitisob- viousthatthevibrationsproducedbylightmustbe ‘much more vehementandrapidthanthoveproduced bysound, ether being. incomparably more subtle ‘han air.’ Afeeble agitation notbeing capable of‘takingtheair80astoproducesoundinit,thatof‘bell,andthatofallothersonorousbodies,aretoo{ecblerelativelytoethertoproduceiaitthevibra-‘tion which constitutes light."Youwillrecollect,thatinordertoexciteaper- ceptible’ sound, more than 30, and lees than 7552 ‘ibrations must beproduced inasecond;theair Blogoosubtletoadmitofasensibleeectfromaconsistingoflessthan30vibrationsina200- ‘ond,butnotsuficientlysotoreceiveoneofmore than7559vibrationsinthesecond.Anotehigher ‘thanthiscooldnotbeatallheard.Itisthesame ithexpecttother:7562vibrationsproducedin secondcouldnotpossiblyactuponitybecauseof itsgreater subtilty. Itrequires vibrations much‘more.frequent. Aaagitationsorapid-oouldnot |$288 place butintheminutestparticlesofbodioa ‘whictlelodeourseaves.‘Thelightofthesun,thea, inproducedbyaveryviolentagitation,whichaffects “ oxranwarnsoF {bisinfitelyminsteparticle,eachofwhichmut SEabsiunytensestneeyoryscone itisasilaragitationwhichTitewiseproduces thoightoftheaedstare,andofllfrensuchCandle,tapers,torches,de,whichgivetigSodsupplythe'placeofthefon.GuningthenightOnattentivelySbervingtheSameof&waxcight,youwilexalyperceivesthatinthetentpartEisTheeicontacaderingtion; ‘snddontapprehendthatmysyeemiafableonislefanyconraioon,wihatofNewton Tiiching”theminutesparticeewitthevelocity etnthen'istheexpansion ofthenaarof isthen,isthee ‘henature bollelominburofthenaelves:forthereareTam ovebooswhichaenoteoimmediatelymuchws {omovnaottheplmetswhicharsnrtoout {dobe,"Weseethemoononlywhenandinsofar sheiniluminated bythetan;andthisi,the *Gaveofallerventilbade,fresexcepted,whichEireaightoftetown.Butotherdie,which redenominated opaque,becomevinetouronly‘whentheyareiluminatdbysomehominousbody.inaverydarknightorintnapartmentvocostlyshutoneverysdefintnoightcanindsdtainaie,13prgoctwlYoutryoureyestowardstt chjectswhichsurround’youtmthearkyouper- etrenothing."Butthefomentataperteihre: ‘iced,youimmediatelyace,notthetaperonly,bak fheotherbodieswhet”werebeforeinvabe,”"Wehavehere,thenaverycrecnaldiference betwoes lay‘andopaquetea.1hvealyae PloyedthetmopuetoSenatebodieswhichre ortranoparent; butitcomestothnosttheame{Sagilyetutaccomodateraretote combonmodes ‘thoughtheyareDot ferfeclyaccurate.‘LuminousbodisaarYiableby Bicirownightandneversectourorgensofeight towmovesoores, 95 morethanwhenthedarknessiotherwisemoatpro- Found. Those which{heredenominateopaqueare rendered visibletooonlybymeansofightthat Isforeign tothem. "Wer perceive them notwilethereinadanefuaontheyae tappedfosluminousboiy,whoseraysstrikeupon{htmtheyBecomevale,andtheydeapeatte tmomeat Satforeign lightiswithdrawn, Weisnot venancenaryhntherayofaminoblyShoalfaaptihemnimediely® aooteropque ody, when well laminated, produces nearly the Sn’ efee, butins feeler manner, ‘The moon isanexcelent instance. We knowthatthemoonisanopaquebody;butwhenshoi iitthmandweoeherdrighe bight,she: creealfae Fela,ntreoderyviotousoeswhichweet sethavapeered towfeaman.”Ped Pyein an apartinent whowe aspect is{owasthenorth, andtowhieyofcourteth fayeof thesncannot enter, itimhoweven, pe.fedclear,andTamablefodstinguisheveryob.‘ect’‘Whateanbetheenoaoofthiscleamee,futatthewholeheavenigMuminated bytheSuntyptonySpartinaadtheatersurround Le‘arte ‘ther surround.SPahecte,areIewise. mingled, ethermme- ditielybythesun,ormediatelybyotherbodies, totheactionofthatfocusoflight;SoiagedtecinofthalcuofLah Borisafaraschanatmastonntomyspartnen, Tenor lamintdintoprwt ‘indownaehigh,wide,andwellaced.‘Tholane Bitteornointerruption being’anhavealready Femerkod,1tranperant body,hicheslytank: ite the Tay ofghtenIcomplyexethightfomthe apartmentby ‘rindow-ahuters, nme-Skooltoaoteofdarkness,anddoceboobjoce enact secerelestere ci,nennme sepia tres eeetereecay Seite. apeaeteraaa se Sparen reneis.hagtaennereve enero Sneraoraares Ee Er ine sp ke e_N S‘oftheReflection ofRayeproposed. dees pineonofopauetotessosomingvnblewenthey aeillummated, itmustbe ingeneral, that SeeSere erinwher Beart eres mace Danes foceiee ites BSseetietnieeutetet netSameer eancrow 2 rafanyennareontykiled)an,thorhaving scanetaSatSeated Sree eer Santee tent Saisee Whichproceed fromtheobjecttous.Ishallafter-Secrets,i ‘onthesubjectofvision,andexplaininwhatmannerShaeeNMaes fevaasShs ‘REFLECTIONOFRAYS. 7 sawesoostiesoiyeahya * aehoaeacdiearhee reSoeare moetwiacte eles torbeopaquebode,orofpultogthemmeaslythesamestateasluminous bodiesare,which,byan Llaiapaa irat sen nt eer gulp ahaveexamined thesubject,assignreflectionaxthecause ofthis phenomenon: itistherefore ofthe Specieteinara FRtani oeny watre Eten am pin xehy a ene need eee sxhoneleaeftbrlerei inthere ren ed ea twocases. LetussupposeAB, Fig.7.Fig.7tobetheledge!fabilliard~ aaBenner Er'thedirectionofDic,peraesBeadicent‘anglesACD=:Bonesjen ie szedocedithecamelanDC,‘heotheconby ‘atheite,forningwitABanseale mdeA.CE,thisiecalledthangieofincidence.A eS ro 98 REFLECTIONoFxavs. inthedirectionofthelineCF,90thatthielineneBGFarectyequalsteangleofneeence leBCF,exacily ‘angl lence Bee“ThistageBGT,formedbytheUnena lekthetlreco,iscalledtheangleofree ton."Andthislawalwaystakesplacewhena inmotion meets withanobstacle. 7‘Acannon-bal” shotaguistwallguffcionly strongtoresistitisreflectedconformably to.this lnw. “itextends, inlike manner,tosoundewhich Brfequenlyrectedromcertainbode;andyou knowthatthlereflectionofsoundiscalledecho.It cannotbedoubted,thatthesamethingfrequently takesplacewithrespecttotheraysoflight.The‘objectswhichweseeinmirrorsarerepresented totushythereflectionofrays,andeverywellpolished facereflectstheraysoflightwhichfalluponitIts undoubtedly certain, therefore, that there. arecaseewithoutnumberinwhichtheraysthatfallon‘certainbodiesarereflected;andphilosophershave ‘thencetakenoccasiontomaintain,thatopaquebodies ‘rerenderedvisiblebymeansofreflectedrays. 1seejustnow houses opposite tomywindows "keoptionafthoesplowoper ieraysofae tothe opinionofthose a,theraysof ginfllteutcofhoehousearreted from them;theyenferintemyapartment, andrenterthesehousesvaletome”Inthesame manner,ifwebelievethose ers,themoon indtheplanetbecornevaleandthoseareanace tonablyopaquebodies."‘Theraysofthesunwhich fallonthese:bodies,andillumigatethepartawhich areexposedtothei,arereflected,andarethence teamedtos,jutafthebodewereluminous ofthemselves, Accordingtothisopinion,wesee ‘themoonandtheplanetsonlybytheraysoftheounehtheyreich andyoumuaGequentlyhave hearditthatthelightofthemoonisare- flectionofthelightofthesunInthesamemanner ‘REFUTATIONOFNEWTON'SGYSTEM.90 trythey,teayeofthewnaereetdbyhe putea satesepctSherEaisofthewanetateaannosect Ofte resectiontitinyacuraWeen ahovorerpasaueSsoptimyte sightapparolen0aysmrdenwhen SeapPEetnnad tha ie toll unten, uchhopetodemounin rfrnont Beissalonoflepomtnenat an, 00 uerree xxv eoninto sndRation ofNev's Syten, 1armn,thentatwinweseaopaquetty antetheuyipsaaaa SePWestehmryetymen Sthtyeieendrdwall oue"Thexpe StanieshichsonnyretethespnaBaye soporthsoplorther aes ILReal yondcent, sdstackfecayewihfaleonbtwhenteneect‘ByerntOureenwtdoheyrepresentHErareyancearaheme, EGUoftomwhchheyegalrose tatteeconshagetbtfal Sahootater iceBelinoe30s aesotstonteslesoftetioet ‘hewnftmaybealwiaatSetnormaneabe onakingtaOpaque,odyunin thesun,wedonotseeinittheimageofthatglo- ‘tunoktwoseeolyteareatebon |GaPeteaiaontdetohem"WeeeSrvthemevryentaldferencebenethe SUEYachoifosor,cheeby innofwhichopbsinareonderrable 1 sesmaraeee merper picseersSecata coeamaa BoosSoechines aiSeeEeceaasen Soocee sommes‘but,asIhavealreadysaid,thesereflected raysneverRoomy sade rekrens BraetSSriaswtseawte Seatoe Spearnaeeeas wesies ior aaaSageantsep Sealersrecoos bodiesbymeansoftheraysreflected fromtheir Anobjection willperhaps bestarted, drawnfromsetae owen capi seacesesetcae ewchange.ButthisinnorespectweaonamySectgedoectnceat Sereenaet coin“Rees Shlyprovesthatthenguarejectaaeetiowed 2haseitace a acces Seng maara Tetetakenface,beerthowmaadordinaryScarceiow,itis ‘comprehend, that, ncuategleandtnguahed omthemannerie Sa?eensate ee chen charaaes Seveseaerases ‘wileetectekenachaonthreapes Ooopoo STPcetetaon abacatnlyvertiranopen Ries eeereeves asmeanteereratase es wealreseeien Seehha areneSeber mca hadieenrcdicnmten omer Pgiedoom"fataarenat Serene ateae Seca memes SetilarSent ah RESERCEGywc am caltionandcontradictions whichThavebeenen-Soo eee ees oteetterRowtoniraeelre;atbe heel eee oetenner ert SalenaotReape ee eee afenoeaitiesap Se reoare iertesotoimaginetotheexpoationoftipe eerie aa \BonenInathardadsingStina sinfcijettwhatever.lewouldtatermaintaintho paceEat eecsoewemimesactsarrnghfmoiomeh. sirstoteraking tre enepenret eocnnofeesenigTaeerelsrteoreenedahe isiSacral Sinanerage sere serene pitphenroa es sie ‘sublimetoberenderedintelligible. IhopeIshall ‘beabletoexplain thephenomenon inquestion, inBeleslOephonepts en safem eMbekhOpe ‘fodleniemisaedbecometale AuttiephenomenaofageSdinwhich1 AitenanensofornDodihich1Seisesiveratooeuerey inated,itisnotbyraysreflectedfromitssurface saeeaereecebemfmers fetbeecabbbe aefeccis atin tehteate rick of mire,SoeieGeo, Ferenc,taheaioeaomgeei selraesforanopaatuebody,howevermuchiilumiseluminous bodies do. 7ir bent attaat,reastinmemesbatstdestehayweartee Steed saatmsefaie fectofeerou iheegcnetyontenoperSshjneetTamanby‘Uluminated, theminuter particles ofitssurface are‘in.astateofagitation propertoproduceintheether car as nanan 18 sesionstrin oh yrpriest ee te PeeCsel ‘effect,reysinustbediffusedfromeverypointofthesurface,inalldirections—as experience evidentlySie Hinata acerwthichiflowthateverypointemitsrayainallSaco coeee setathatectbintineargrgeeares Seehefiriclaa test ee CaS ia Soe see Ytmustbeamited,then,thatwhenanopaque arananeminrs oe Rina ae es eathecavewitboisIinoBftema,ieightofteifumisatngnyoreteas Feltoeiginlet ony:ydaylight,‘inthehghtsimeby ‘apersorby hemodatheatcaseaiage Pead demic neyane Peseta ates hoe archaea Peete eeeer |SERRE Sho retsamecloseroom,orintothedark,nothingisthentobe iesneintienes petertartteet Sntrcmtmnoe 'Goceight.Butthesesameparticles ares0-die- ih sreOtaer Seo aacee 104 oPAque nopmes LOMINATED. tion,ormotionofvibration,propertoproducerays; fin'the morelatense thelightfowhichlaminates ‘hesebodies,themoreviolentalsoisthisagitation. ‘Aslongasanpagebodyminted,itinthe ‘same state an luminous bodies; itsparticles. are tatedinthesamemanner,andarecapableofex- ‘hing, ofthemselves,rayaintheether;withthis diferenc,thatthe agitation keptupin.Tamineus bodiesby'an intrinsic force subsists alwaysofitselt; Tiomentaryandhodacedbytenotionoftheight momentary, ince‘motion whichuniteSemnomenonaadlaboursusdersoneofthedticliosThichdeerminedustoabandontheother,namely,that founded on reflection. Whoever will taketepubecandidlyYoweigh allthevereasons must ‘Admittheirforce.“Butaverygreatdificultyfemaine besored:Nowcomathatnin fatetnagedexpatofprodecingwereek thatthisagitationshouldalwayscontinuenearlythesame,whateverdiferenethremaybeinheAueTacknowledge, thatwere itimpossible toanswer‘thisquestion,itwouldbeagreatdefectinraythe-ory,Thoughitwouldnotsmaunttowcomplete rehitation: foritcontaing nothing contradictory.Sopposing’ Iwereignorant howifuminationdincesanagitationintheparticlesofopaquebodies, thiswouldonlyprovethatthetheoryisincomplete gaatiltisdémntrated tobeabsolutelyimpons lumination should produce thiseffect, cumsubeutsalaferoup- athemulapriedofboden ‘behJuly, 1760. | . i riers sons uurmaro> 108 warren xxv Continuation ofthesame Subject, ofanopugueboymastprosuceistminutepre niecesfohaeNfemit hipaa popescaeearoa StRPee ae meharcu oeaye rate,neorecomeenwachacayrere loend mee, at bsg hegepageree or Seger miming vote metba copra oo eroseteseoe Seitemf natestistbe WestBoyarent al ep Bsumcensormypoyatoundee SegaSinaawhewet amine See ee ee rae em Ta es, ng fred omge soeamenrehabeGraeto sprintmelateouwnsbepee ye ag fa rm aaeofFak heybrugitniepneu the sopetotearnest ofveto2; arere rrey serrarterstaariooneat Norgecoe faringconcerto attendtoparticular eringi dering2 apesaeETT netsTeal es |emitthosamesoundnnfithad‘beenimmediatelyeins ence pet ed Aa pe peer Sse Coe pen oe eee se0 ensues soomsnsoeouren.veebapyrpetopesihee calaevil oatbait aean ee Satoh aramaio can aaron mara ryeyih erestat cpnysoeeonofeet Sar, emia arta ‘chord ivagitatedbythesoundonlyofanotherchordSoetoro ofart fromthefiat,Bat‘itmustbecpmutyedtat itefobata Tere amon oart eryityrioreomett firmation. Intruth,thephenomenon obeorved by ferte,ktanlepenn eredieee ee re auaaseePRFefeet totendie otherwillbeginof.itselftotremble,andwillemit ghrp oulepiann ieee,ieeen lc et ‘motion ofvibration similar toitsown, the air, agi-Sen pene aoeSuter ms taribaiether atHore einen smal men, htfneemoehnrerI ee ret ne epen byitstension accord withthoseoftheair.IftheizleacrenoheIoe hare ens ce Eeleaetimmatociety ‘OPAQUE BooiEs Livuwate, «10. veryvibration,asintheprecedingcase,but,onlAtthesecond,orthetid,orthefourth,whichwl Continue toincrease itstremulous motion, but less ‘than inthe first case. ‘But ifthe vibrationsoftheairhavenotanysimple relationwiththatwhichcorresponds tothochord, the agitation ofthat fluid will produce noeffect ‘whatever upon it;thevibrations ofthechord, iftherebeany,notcorresponding tothoseofthe Aid, thefollowing impulsions oftheairdestroy fortheImostpatttheeffectwhichthefrstmighthavepro- duced andthisiscompletely confirmed byexpe- Fience. “Thus, when achord isshaken byasound, ‘hat sound raust, inordertoitsbeingperceptible, be precisely the same with that oftho chord. Other sounds which have aconsonance with that ofthe chord will produce, itis true, asimilarbutlesssen- ‘ible effect,anddiasonances willproducenoneatall, This phenomenon takes place sot only inmusical strings, but inallsonorous bodies whatever. Onebellwillresoundbythenoiseonlyofaxotherbell whichiounison withioratthedistance ofan etave, afith, ora third. ‘The instance ofaperson who could break glasses bevoicefurtherconfirms whatIhaveaanced,4glasswaspresentedtohis)bystrikingit hefound‘outthesanehethnSegafoaquainunion,andtheglansimmediately caughtthevibe ton; proceedingtogivetohisvoicealltheforcehe ‘warablealwaysproserringheunison,thevibration ‘oftheglansbecame atlengths0violentthatitbroke. itiscGnrmedthen,byexperienchatchordandeveryothersonorousbodyisputintovibration itsKindred sound. ‘The same phenomenon must takeplacewithregardtoopaquebodies,ofwhich |entnuier parea maybeputintotaoofa{ationbyillumination only—-which isthequestion{ tosolve. ‘The following Letter willcon '2more ample discussion ofit Pe ‘84hJuly, 1780. - 108 exaahzss ano cotoun oF LETTER XVI. Conclusion: ClearnessandColourofOpaqueBodies ‘msc Armawhathasbeen Jotbite0yourcom sideration,youwilgoingerbosurreal asSpeenodyuateofScere. thane foualone anagiton initsparticles similartothat Ofparce oflaminouy Dotien,andwhic vee Shem vayofproducingraethatrendertne inibe, Whosthegreatobjectiontomyexplanation 2ityofepaqodinihapplyremoved: ‘hiletheothertheory,foundedontheTeGectionof Taye,hastoencounterdiffentieswhichgrowipro- Forlonanyouattempttomakeamoredirectsp Beatinofthemfokaownenomenn Teinthenaneetablohedruth,thattheparticles oftheurfacesofallbodieswhichwesee‘undergo Biagistonsma wothat of«chord txvibration, "iraionaremuchmorerapid,whether {bothatthiswglationfstheeffectofanlotrinale force,eninbodesluminousofthemecives,orwhe: theribeprocethereeofihewea ‘ponthebodies,tdistosny,byiiumination,as hecaeinonsevodies.Ttfae,then,tt toon,beinganopaquebody,reectstbeve thewun,andtitbymechsoflelectedghtshe {stendered visiblefoun,ascommonlyandefetood, Burtheraysofthewun,flingonthesurfaceofhe soonexenitparesacoaamionrmwhich Feraleeeamoonandthencuoringats =‘iaimage there; It'sthesame’ wit,Bees,whlopieodin.”Ta ingtheiuminetson wachGeoeaseof;an (OPAQUEBODIESILLUMINATED. 109 assossneprsetycreomieEee wastes ae tasungioneetree eet etn form orttee aetaycderenehwtLee reeBh eeeSeoeeeneh,MoraServe their light’ forsome time, though conveyedSereHeyioteienereed as a tin oremgc ees Sie ee ph gh ysSreecrated BeaeoesmateSbcmeareceie ie Itisundoubtedly certain, that we aninfinite alec eas areecording tothevarietyofthebodies themselves.ieee ahaa at i riaececesoe, ster ienode ema Te ssreatirecrers ecu ee FEeueenatessteep Sree cats eaey iealytngYonaor Setdire,romeSeresannn fc,Sineteenireaes bodies,respectingthenumberofvibrationswhich Eeeried =Parsahelycerathetetpet |alwaysbeverygreat,andthatthesubtiltyofether rarergaycathel feaZaevcrsaermeo BiteSimeaynaanas oe ee 110 cutamrase-or oPsgve nooes. inasecond,andothers11,000,19,000,13,000,accord- Ionesalenneoonadtieany ofeachwinthecheofmusicalchordwhicShenaeovationprenssecondnybe tariedwnihoutond:andtenceitehaveded thedifferenceofhighandlownotes.Asthisdiffer- fyrhinamannertopercearsetrenterttheaTmanner80particle6renee Bontatonofthewhoistheoryofmaneitcannot healedngrthtnirinoe encyofthovibrationsofrayaofLightmust producevariation‘parca “visionTf,for Examples particle maken1000vibrationsfatecon,andproducesrayofthesameepecien,theFoypicheerinatnoewaletemeres Thatorgan10,00timesin'asecond;sdThis ferentfomthoseproducedby=iderentpavicle romTaierent pert‘richchoull meketoreorfonvbrstces ineconTherewilbeinvisionediferencesimi {Stetwhiehtheearperceiveonjhesingharpor fatnotes‘Yournodoubtbedesiroustoknowintowhetthisaterenceinvisonioborool;aadwhatSiterent"sewacn.creeond tie mborteanofthevibrations never’ GrayTurigetecond”Theve inehonourofforing,latvenofsousScatonedby thksZittrence;aadtbatdferenceofcolourfe"6{heorganofisonwhetsharporfasoundsaretoihaWearene, foreionong i,theimportantinquiryrespectingthenature Stcou, wieasoheyedtetention Fi crnBomeofthemhave aedfamtideaton ofightabeotelyeaknows foe,Descoermaintainthatcoloureoniy8 Seriasarofighttnshade,"‘Nowiontae‘countsfordifferenceofcolonybytringitupto therayofthemunwhich,aceovdingtim,area areasorcoceves. mn ralwhosematiormaybemoreot Taititinsanddeesstig"YePSESS colours,asred,Jellow,green,blue,violet,&c. arteseetalicesoftelehattasboosuitepecingsobresoveyenemore=MansayouhebokcoatweehietaeErteprecedeceretinebyibepales ‘thichpresent thems19theeye. ‘12th July, 1760. LETTER xxv NatureofColinpater Tewhich prevalld reapectng theseamaster ichpera, reposting,i ‘violentdisputesamongphilosophers; eachofwhom madean toAhine,bymaintaining ‘apeculiar Spatesonteembesayahemeelim oie inbates Romero paced Baeosraghedtoehemor epeeongvastwttortheae ple"pcie donates ponred, verblue,andanotherrroenthephil Peeae it‘thecontrary;andheaccordinglyaftrme aateteleoltngfelolessndattheesaotdiretehe ‘tobytlecioouaye aylp tesEneycntaly serrateSchantuthaelowhetitrehees Herrerateciee“Siker’to shomtusoptaon Telmea ‘amut prsind tht colour ext oa at {Gortontherlgartightetersbaietat HET atteaanedehpure ns NarunsoFcotouns. ofcolours thanthemselves. But willre:Percale tnttheweafetedretncmenis romeFor.Everysimplecolour(inordertodistinguishfromcompoundcolor)open0atinae a berofvibrations, whichareperformed inacertain ‘eoiemanbefraonn,aden ._,fitondetermines teredsolo,othertheYo iow,anothertnegreenanotherthebie,andatbeviolet,whicarethesimplecoloursrepresented tourinterainbow,"fythenytheparticlesofthesurfaceofcertainbodiesaredispdeedinauchamanner,thatbeingseinetheysaeincnanypateolour,Icallsuchabodyed,justastheclown SeertaYeeoologiestenonfordeviating fromthecommonmoteofexpression, AbdTayeene ach'W"umberafratoie Tecondmay,wi riety,bedenominated felreyes2dtaal.wientheSpcwewreieaf fectedbythesesamereys.andreneclrin eae‘them {=numbeofimpulsions,seoattyequalinnsecond, ‘wereceive thesensation oftheredcolour.” Here verythingisclear;andIeeeponecessityforiSottingdn‘codmysteriousphrases,whlchreallyean nothing.“Thoparallelbetweensoundandightissoperfec, thatholdseveninthemisesclreumsencee ‘WhenI'produced the.phenomenon of&musial ‘hor,wilchmaybeevettadintobrationbytheTesontnceonyofcertainsounds,youwillpleasetoeeollect,thatteonewhichgivesthetnisonofthehorinquowionithemostpropertoshakeitand othersoundeafectienlyin = Srvinconwonencewithieenexiclytuenam ‘btoligtandcolours;forthediferentcolourscor-derfodnplaytisoentrenoe, which “orderfodisplaythphenomenon,Whichcom pletelyconfirmsmyassertion,letarkToorbo MATURE OF COLOURS. 13 Provided; makeasmallspertureinoneoftheshut-tera; before which, atsome distance, place abody‘ofacertaincolour,sayapieceofredcloth,60thatthenitalumipeisrayemayenterbytheaper-fareintothedarkenedroomTheraetustans.tatedintotheroomwillberedllotherght beingexcluded;andifyoutolontheinsideofthe ‘room,oppositetotheaperture,apieceof {hesamecolour, itwillbeperfectlyilunined,and iteredcolourappearverybrilliant;butifyousub stitateinitsplaceapieceofgreencloth,itwillre- fainobscureandyouwillarlysee,anythingof itscolour.Ifyouplaceontheoutside,beforethefuryaplecoofgreencloth,thatwithinthe chamber wilbeperfe€ly Mumincd bytheraysof fhe‘fra,andfagree.Cloutappeatverylively,‘Thesameholsgoodstoallolercolours;andI do'n0t imagine that«moreconvincing demonstr-tionofthetruthofmysystemcanbedemanded, ‘We learn from it,that inorder toilluminate a body’ of certain colour, itisnecessary that therayswhichfaluponitshouldhavethesamecolour;those ofadifferent colour notbeing capable ofagi-tating theparticles ofthatbody. This isfurther ‘confirmed byawell-known experiment. When the spiritofwineietonfrein#room,youknowtat 36ofspiritofwineisblue,thatit nlyuerays,andhateverypeeoni,feroom appears very pale—their faces, thoug! eversMaeep,havetheaspectofdeath.“Thereasonia Srident;theblueraenotbeingcapableofexciting ‘orputting inmotion thered colouroftheface,you seeon itonly afeeble andbluish colour: butifone Ofthecompany isdressed inblue, such dress will ‘appearuncommonly briliant.Nowtheraysofthe |sun,thoseofwaxtaper,orof2commoncandle, Hisminatealbotsalmostequaly;fomwhence itinconcluded thattheraysofthesuncontainall coloursstonce,thoughhehimselfappearyellowish 116 raamnanavcr of soos ‘Intrath,when admitinto»darkroomthesgolathe sonecolt, JeiowEE,Solenayopeluae thes thy yopenet Alin ono ene Std (rel eae poder Slo Seidmater ong macpeers mish Shine Sth soa Honcy WenchSEoatsSonscolonbtttinthe ‘Compound ofallthesimplecolours;accordinglywe SPRRaTWhe aac teseceponooh Siowatoak’antproperyelo reyodyseatwhenfeces aeseck {htcnTenneson orationoFwhen iPSamotpoderapetewantofpeereoryridesthciationhtcola”ate‘moreparticlestherearefoundinanybodynotsus- sorbofayounofvraiobera ‘SPrmore Hach andobec tapeae 15th July, 1780. LETTER XXIx. repreofBoiiethnmin Imavealreadyremarkedthattherearebodies, sotilalplaceraespe weaese Ilefayegeoseta a ‘ertyaredenominated pelluid orciaphanous, Tbe thie lomerer, se aed awhch oeFaye ofAgiateformedtowishlsproperytoe ‘matelyappertains; andothertransparent bodiesare siertewcesernee ee ieetindaeeronyneal Sor Shireen avo ‘TRaMePARENCY OFSoDtEs. 8 endowedwithitonlybymeansoftheetherwhich theycontain,andwithwhichtheyare90blended haltheagiations excitedbytheightmaybecom rmunicated farther without being interrupted intheir ._But this transmissionisneverperformed 20freelyasinthepureether,thoughitalwaysloves‘something;andthisinproportionasthetransparent bodyismoreorlessgross.Thegrosenessmay ‘even become 80considerable thatthe light shallbe ‘whollylostinit;andthenthebodyisnolonger ransparent.‘Thus,thoughglasebeatransparent bodyreatlampofgiesseveralfeetthickinnot 0.Inlikemanner,howeverpurethewaterof& Fivermaybe,youcannotseethebottomwhereitis TEdeepthoughyoucanverycayweetwhere “SPrumparency, thenisapropertyofbodiesrlthen, isa ae tive onlytocthikneenawhenthipropery fsascribedfoglass,towater,&c.,itmustalways SeunderstoodWithhiestcion,thatthesebon ‘aenot100gross;andthattoeveryspeciesthereis {certainmeasure ofthickness beyondwhichthe bodyceasestobetransparent. ‘Thereisnotone‘opaque body, onthecontrary, which may notiteelf Become tranparent, ifreduced toapateextremely fine. ‘Thus, though gold isnot transparent, gol leat9andonexaminingthemincterpartilen ofallbodieswithamicroseope theyarefoundto betransparent taythenbowthtruthaffmed That all bodiesare transparent when reduced 10a‘certaindegreeoffineness;andthatnooneis#0 "income ti denominate transparent speodienwhicpreservethiqualfo#crtain degpeeofticknen,thoughtheyloveitwhenthey fobeyond tatbound. Butwithrespect tother, Wis ofitsown nature perfectly transparent, andits extent diminishes not this quality inthe smallest degree. ‘The prodigious distance ofthefixed stars is saarnaaser or tomssnotttegeomtingepio SmaBteerfemteeorate Rempncy,sedeawewak Taeparece ao reEeReeioice ran Ee te ae mat te actinieeneeeee smeyignore ae cine oe Speearnytame, seme met soemrteregiofsane iw uated eg cect stings erieofterenaesae ioteberteeeSeaexerteet haan rat ie eae Bosom,Teeonsonmek piericienhtheatregira eatealee Feoameen’ ea hansomeed Sstey dn hysepecsinfreitiro eae eee Beeyeseeean eesoliSmt ectoeapetenf eea removed, youwould undoubtedly hear more dis-Pa aedfiicwou tenlorah nothingcouldbeheardfromwithout,unlessitwere Pengelemwieetwee ezrin oyfeelehae TEESE arenes pene orSeperate optsrmleeswile i ce cunningeaace (ofthowall,butlikewiveshe’strengthofthesound. a - Jd ] ruamraxencr o7Booms. LIT thesoundisveryfeeble,averythinwallisutt- cienttostopit;thoughaloudercouldfindaneasytramiason, ‘hesmethingoldeatobienDecta notveryWellaaryivicbleUnugh8 fieblackenedwithsmoke;butherayofthewah Fehamniven through andtana pr. fetlywelltheImageofthatluminary. Astrono- ‘mereemploythismethodtoobserveitn;forwith: ‘outsuchprecautionhewoulddaazletheeye.“And‘whenyouhappentobeinadarkroom,withanogre tegateexpowed teuavan wil youat exe By oppostpoland ipapetire;theraysofGesenwilemcee rg, Ttisperceivable, atthesametime,thatthelight fhe nopechfunsanghog bodywhchlively totheaeotaButaverystronglightmaylovemoc titLotebeforeiearlyextingulgbee,while Afecblerlightielostatonce."Apceofverythick fase,then,willnotbetransparent withrespecttO{Bic ny, hghthmummaybeoe“Theseremarksontransparent bodiesleadmetothetheory ofrefraction, ofwhich you have. tre-Teaarwhichhlendareurtopce 18hJay, 1760. ] 8 orm maser bevren xxx ‘theTransmission ofRaysofLaght,through 1heTHeMedanandtheeRefiacaek sy stg cote see mtn,witha aet stecr iailreoeeeShierewanmacerantt waspentane temasHilitowheein reo maresnarrug hese hang inett ommend te ppphe Nae | irenejieforaero Slitmeeracter eee srl pg nelsiesincntecononurs ie owiehe acyoe tolaydown theprinciples, inconformity towhich ily dive es “Hite ry sereeaes enemeci Bea ee aan og pedir ae ats re fr pa hh ee 2 ee, Side wos emt islikewiseperpendicular t0thesurfaceAB,60 (OF RAYS OF LIGHT. 9 ‘thatEFshallbeinoneandthe‘samestraightite. "Thisistheonycaveinwhichterei'n0 Teftaction, Butasofenasthemaydoesnot fall Ferpendcalariy onthe surfice offnother transFarentbodydoennatparseitsprogressinthe Eestraightlinesitrecedeslessormorefom tot undergoes aietaction cere a orientheste , foekBofanothertrans.parentmedium. Onenter-Ei tirmediam, squireiproprei . thedirectionoftheTine©Q,whichisthelinePC .7batwilrecede Femi inte dreclon oftheline@'R,or68.Tt rlundergo’ then,athe matGybending, which wecall refraction, whichKejends perly theaiferenee ofthetwomer diums,andpartly‘ontheobliquityofthedirection atine my BC. __Inorder tocomprehend thelaws ofthisbending,itfnneconarytoexplaincertaintermsemployedingthiect iu hesurfaceAB,whichseparates thetwo modtime, that from whith the ray somes, at thatitowichtntiealedtheroyrece ‘dly,TherayPC,whichfallsuponit,iscalledthein-cidentray;and,‘aly,therayCR,oFC'S.whichpur- Semin he ether mediom, acouree diferent fomGQscaledtherotenorracedray."And.haveingdrawnthrough thesurfaceABtheperpendicular \leGF,wohytheanglePCEormedby the incidentrayB©eittheperpendicular8G, Beaneoftds:aSlyiwnageCFot SFYformedbytheretractedCRorCS,withthe Derpendicnlar CF,tscalledtheengirofrefraction. 190 -TuunemauoxoFsaeoF-1i0nr. ‘Therefore, Becauseofthebendingwhichthemy ofgitundergoes heabeofserene akSealtotheangeofsnedenceFOforprow ‘SdeingthoinePCt0Q,theangieaPCEandF GQ,beingetalaoequtoeachotes(BchEi ‘ments,Bookf,Prob.16),asyouwilleaslyrecol- Tet,"TheangieQCF,then,iequaltotheangleofincidence PCE;thereforetheleofretraction RCPorSCFisgreaterorlee.Thereare,then, olytwoeaseswitchcanexittheone,inwhich the’refractedrayboingCB,theangleofrefractionECFinessthantheangioofincidencePCE;andfhesterinwhichthereactedrybeingCSthe apieofetactonigreaterthaheangeoffe ceBU.inheformrcaeweauthattheet cularOF Botheroutthereactedray©8revedesorde- ‘itesfromtheperpendicular, tisnecessary,then,toinquireinwhateasesthe coneortheother’ofthesecangeswilltakeplace.‘Roto shalidthattiephemoneaon dopedoo ‘heaiferenceofteJenatyofthetwomola,or UigealythoughsichofthemToprovefie1 ‘cachofthem."Toprovethin,i must£erecollectedthatetherisofAlmediaias themostaveandthathroughwhichrayearetrane-initedwithoutthesligatestresistance, "Afteritthefangedir,water,gasthanglamiemogion,alr,water,glassistmediam Soredowsthanwater,wartananalthan“hisbeingaiddown,wobareonytoattendto theaetwogeoeralrea’Tat,When om *octunfwdnstoOnwichren,ie actedtayapproachesthemore ene cular,‘Thisinthecaneinwhichtheincidentray beingBc,therefractedayisCR.Sily,Whenthe ‘ayspass{romsmediummoredenseto.onelosswo, {Reracedrayroutesomtheparpendicnlar. ‘Thinisthecueinwhichtheincidentreybeing, mamicrowormur, i POherotatedrayinC8,Now,thibandingin fprserorlaraccortiogaheted der Erregoctofdiy haeayes yung trom tintplaeeundergagreserchonawhen {heyuefrartster,InSotheveoe tertherectrayesprosh heperpenInlkemannerryefalomfietr Atrg'areneerationtianwhenfeypasom sro lf sr bata these ce thofoaeted ay ‘Reson trom theperpen Fin mancebeFordath treesCewernhagocanetndtheeg seraction toachgatorthagoe laracresort Tiident rayTeedee fetertomiheperpen tegrente wilbothobending orrefachonotteray Xenon be tween allthese angles exists, andisdeterminableby Feeneyatint now ecw foolerig KodeWhar has benalteuty at eterferanderianding whathvefareropesot ecsdJy,170, Leven xxxt. RefractionofRaysofdiferentColours. ‘Youhaveseenthatwhenarayoflightpassescollomonetransparentmeanfoster ‘Pegsanigch,eldecto talthtiheretacios depends ontheobi a fie ackence and theSent ofthe medias “Iienoweasponyoutotemsthatsvessy Siyarrmecaeremce genesSpiniefeaceipeatome Seonserena mae ieee .Vict 13 REFRACTION OF RAYS ofcoloursoccasionslikewiseasmallvarityintheretraction. This arises undoubtedly from the ci- omntance thatthe rayswhichexit nusthesen ‘ationsofdiferentcoloursporformunequalnum- bersofvibrationsinthesametimes,andthatthey difer among themselves, inthe same manner as sharperorfattersoundsdo.”Thus,itisobservable thatraysofredundergotheleastbendingorrefrac- tion;afterthemcometheorange;thevyeliow,the aren,teuctdtheileflownore;6that ‘iolet-coloured raysunde strefractioniebeingalwaysInderstood thattheobliquity ofthe incidenceandthedensityofthemediumsarethe same.Henceitisconclodedthatraysofdifferent colours have notthesame refrangibilty;thatthe tedaretheleast,andthevaletthemostrefrangible,then,P©Fig.10,iaaray ing,forexample,fromarFig.10. Fitopines the angloofincl.denswingPHtherefracted GiduarCPsanditheraybo red,thorefractedraywillbein thearetion Cred titbe orange,therefractedFaywilCorengesandsootherest, asmaybeseenintheBgure, Altheseraysdeviate fromtheline©,whichisPCproduced,towards’ thoperpendicular ©F;butthered raydeviatestheleastfrom©Q,orundergoestheleast ‘efraction, and the violet recedes the farthest from €G, andtndergoes thegreatest refraction.NowiPCisarayotfheuntproducesatoncesiltscolouredrayindicatedinbegure;anit 4pieceofwhitepaperisplacedtoreceivethem, ouwilineectwoeallthexecolours;henceit1s{iirmed, that every rayofthesuncontains atonceAllthesimplecolours.”Thesamethinghappensif or paraassr comomm, «18 Poinaryofwhiteortproceedsfromawit body."Weseealthecoloursproduced fromitby Pezeuoncoe itcoset tawi ookTroubles atheapecolouraewefone {Sloerayneagpoaithecolorof raynint'singepnandtheaoa ‘whitewilBetheresultsinteraverwhatrothsnpclue natactonRdcmigesthemicone“Iowaheodormichftresetteytethese’ 1,red;2orange;3,yellow;4,green;8,blue;6,dks mat 266 inl tat hres Talc, rasdforene otcols ares fo the tanbet ofvaraion nick rays perro and Shenae tineoer heito whchpethethemcarathetres ieepicolores‘Belvoweamames SFrticl'todelgratothesecolours;forbetween Patoanteranevenlyforceneraeds Roma bfUitte hire LWspato names iaafl toe ane leew erpotacel the eareaare, Fap at eg coh We top ofwatwkdoe Hadabeuebyeffected sodreacted, yietnlecbppeeinent Sours Voumnstandettedyharerenaredthat ierleursloehobenaeoe nahnheuhroseglowfraKee malaybatedocoWidaltormedatelkedetofonecelefoscartoad Seacts wanes ()aitagunh tines ages Tiida ne ofthm ase neextoy sryenegyeetntertet |Seay SareesEoceneRaconcieas errPoderyRemortgage ogTey | 1% aaruacrionoFave, fheother.Amorecopiouslanguagemayperhaps tenable another nation actuslly10reckongreater ‘Sumberofdiferentcolour:todanother,itaybe, tamekonaayforexampyware Sammtocapresewhatwecallorange,Bomtothee £22plwichwrprevatheeateityof theFoubat’waicholbereSomprehendunderthe fetosbarewithfe op RR @ AB aeo8¢ ;E eGR;H } ‘Thewecoloursmaybecomparedtothenotesof anoctaveesTneveZooshore,YocansehoFoon ‘Stcolony'selleshoweofsouat;mneybeexpresod Symutate:“Thereiaevenansppenrance,at Stainingnatiemrefaaycoteround fovapewtpurple,jstasiningfromsvntowound, fngorngbeyordB.youcomeroundfoe,whielis Goofocreabove02°"asinmunewegiveto thesetwonotesthesamename,because oftheirreopnibance, thsuotingfakespisosgolonre,which,afterhavingrisenthrough theintervals ofan‘clave,resumethesemeuuoeeorifyouwiwecolours, liketwosounds, inwhichthenumber of‘brationsinthooneiprecnelythedoublofthe‘iGfsorhateandottosaene faispriacipeitwasthatPatherCast, Franco,comtivedspecieofmusicofcolours,"Heconstructed aharpsichord, ofwhicheveryKeydis-Bidetseabeianefwcvcoloranpre. ded that this harpsichord, ifehlflly touched‘wouldpresetsmostagrooulospecaclovotheoye? HouvetthenameoftheOeuerHerpeichord* and ‘Dervamatsrestoontasalaasocspsina soos cos0 ormax ative 18 seem ny tanned amiatimtakemair etbewhether therepresentation ofseveral shredsofcloth PieaTeae syeae i Of Awe Ct te me Ye ert tn ofeh oj sae iy Shether amar cana SafaentearsERLE, agitatedbyanintrinsic force,asinluminous bodies, Seg ABege OyenHee Gr ls ah el Bair lt eePek rg tcc ur ty are iecery Shecta ts Ses ers naa Hefei heaia aeekayyci oy Perot Eveaylt SoSoecece eeer mecorescetietoychonSeeeaharebernitae |SERScpr teoe ioadtet ening igclarerth USahctema ty eveaefetany Sn Teepectingthisprejdice:2amadegreof 198 (orTaxAxonscoLovs‘tionissufficienttomakeyoucomprehend thatthe heavens arenot anazure vault, towhich the starsSroalgedtke90manyluminoussade,Youarerfoctly convinced tint the. slars are immenseoticctinconcetabl distancesfromunandwhiehmovereythroughs spacesnotrtorwich Bhdolybythatsablematercalledether, ‘AndTwillshowyouthatthisheaomeaon itobe ‘ascribed toouratmosphere, which isnotperfectly trAeeeitpossibletorisehigherandhigheraboveee possible : the urtaceofthecarthehehewouldbecomepate tallymoreandmorerare,tilitceanedtositelton, tndwoulatgterly cone weScaleshaereachedterpionofreether ‘Accordingly, inproportionasweascendonmoun:{aims the Wercury’in thebarometer continues 10fa,Thacruoethestmoephere becomesgharand Tighterandthenlikewiveitisremarked,thattheafteouroehaarbecomesfeyand trereitpossetomomtintoporeether,twSirelydisappear:onlooking‘apwar,weshoaldfeonothingtal,endtheDeeveoswoudsppoetbikemasforwerenoryofghtcaFeach averery tiogwear theappestance Stback. “phereisgoodreazonthenforasking,Whythe beavengspeartobebe!ThispenomenonZould botoustweroata reatmedia 4potherTacinthatCase,w0shouldreceivefromKaseofdapaogreatthatthefebleight astreOFGaylis90greattatthefebleOfthestaresabsorbedbyit."Youcouldnotport sivetheflameofaperiatheday-timeatanyGonsiderabledistance;butthatsameflameinthenightSoulspear eybilan ochree tances. 1isclearlyproves, thatwemustlookforthecauseoftheazurecoloaofthoheavenstathe Wantoftransparency intheai.‘Theairsloaded. with agreat quanity ofstall parices, which are on var wzuvans at not perfectly rent, butwhich, being illumi-tedbytherayaoftheoun,receivefromthem&Bekinofvralnotcpescnwayoft fiWor ele fey9Somnietoafromboingsmined Rowse color ofthet pailen iBoe; and tus‘ crplaina thepoonomenon thetrcontlng a ret quany ofa Sepia or maybe EEG" ots ater parte aelob, btt's Snlourexremely deli, andwhich beeSmos seatSibuolyianenormousmanofsirThs,2°room,wepercey stan ofaiebe Theo ibis Pays ofthe whos simosphere ene Tis cureyes atae, however delet thecolorofeach singly, their totality may produce avery deep eoturhisiconto byanotherphenomenon, withwihyumtbepelnegunited youlnka rheTiies moeiedaues sigan "atmproportonasyourdanceinereles Frecquires« bushcasandthigraduallybecomes secpetnd deeper. Thn foes one ssa ofTact nayteseonomMagdaDearthencetobebive,butviewedfromSalbersiak, Teepe green” Thegret extent ofsrbetween ‘Magdeburg, andthesemountains isthereasonofit. HoSererfeatorrarethetnepreofthe Hoey be‘there such sroan goanty ofiowatrvtnoayeofwhieheneotofiveroace,utfeyrepresenttolerabledeep bie? nba merrier eet SEESLSEee eee \Sparcsy satsotefecpeaUaeebccaeSeatiTherefeston oftheMeerayom fastoa ae gee moet meee aaotees eee ed 138 ovmars,AxooF‘Weromark1similar phenomenon inafog,when toeaiislodewithaeatgunnttyofopaqueTallstance,yousesreey perceivethogbat E'emalldistance,youscarcely perceivethofox:rotedistanceincoatere, hevetoiow mesveryperceptible;toauchadegreethati Bimpooobic8soothoaghit.Thewaterofthe feaappearsgreenatacertaindepth;butwhenyou fakeupaemallquantity,axmach,forinstance,asa flareilconti. iguclenlydaphanows, wd : nogeile oolar:atinagratexten,when wards90manygreenish Tollected produceadeepcolour. = ‘Ah July,1700, LETTER Xxxm. Rays is @distant luminous Point, and OFRai 5 ‘Aslongastheraysproducedbytherapidvibre- tionoftheminerplotabolymoeinte sametransparent medium,theypreservethesame :{Sriordiehemesialldirecting, a straightlines.‘Theseraysmayberepreseat thesidof'scircleorPthorofasphere,Which, issuingfromacentre,proceedinstraightlinesto thecircumference; and itis onaccount ofthie re- seman tatwepaythenameermad,ot ay,toexpressthem, 5 the ioernotconmstoffinesbuofveryfapid ‘vibrations,goingcontinually forward,.in thedirec- tion ofstright lines; and, forthis'reason, light Ceratemnineteen qnvtyhe oregreaeo. vm roe nee ‘beconsidered asstraight lines, issuing from ammm sinhpeii entersce ioees op eee feiracveed (2) SttherenterapioreAUDBoThoHight,she, rear careers Be em Rey it Schaar tS theluminous point. Ifwesuppose thattheradius Pea nai rinses Saree inane nous (Pagetcere Dea light atdouble thedistance isfour times more PeSatestaeASEasemt wilappear,thatiftheearthwereremovedtodoublehae yeaa Bretrema ogcihnrc. soofo Pian tymigteg ed Hotes StSes ae punseenreenreireimermtnerine|Seseieoet arnejerostoeenaes eeSareesTacttheraboubenodarkestSam.Ba 190oynave,ANDO”THEVInUALANOLE,‘sun,botthatitwas400,000timesfartherfromus,fitslightwillbe400,000times400,000,thatiy160,000,000,000 timesmorefaintthanthat.ofthe sun,Hencewese,thatthelightofafedsaris nothing comparedtothatofthesun;andthisisthe Teatonthatwedonotfosthestareinthedaytime; asafeebletlightalways. inpresenceof ‘onemuchmorebright,Thesamethingholdsgood Wilrepecttocandles,andllotherhumisous Yodieswhichadminister lesslightinproportionto theirdistancefromus;andyoumutevequently marked,thathoweverstrongalightmaybea {insufficient toassistusinreadingaprintedbook,it ‘youremovefromitoanyconsiderable distance. ‘Thereisstillanothercircumstance closelycon- nectedwithwhatIhavejustobserved, namely, thatthe’samo objectappearssmallertousinprooriontolisdistance,”Agiantatgreat dix ©doesnotappeartallerthandwarfnearus ‘Toformaclearerjudgmentofthis,itisnecessary toattendtotheanglesatwhichtheseobjectsareteenbyus. :‘Letussuppose, then, Fig.19.ABegihtobean ‘object,orexample,« aayodthattheeye 1ookeat itfrom int6.Drawtom hatpointthestraight lines AC.andBC, which represent the extremeraysproceedingfromtheobjecttotheeye; wecalltheangleformedatOthevirusangleof {hatobjectforthepoint."Ifweooatthesame ‘objectfromasmallerdistance,atD,ihevisualangle ‘Dwillbeundoubtedly greater: hence itisclear,thatthemoredistantthesameobjectis,thesmalleriitsvisualangle;andtheneareritapproaches, itsvisualanglebecomesgreater. “or vistox. 11 Astronomers measureveryaccuratelythevoltwithwetoetheHeavenlyDodie;sodey ave found thatthe visual angle Ofthesunissome-thatmorethanhalfadegroe.Ifthesunwere triesafarfromthisanglewouldbereduced ttealandthenitwilnotseem,warping{hatitshouldfurnishusfourtimeslesslight.Ceanwere400tesfarterof,hnvuangleouldbecome,s0manymileTee,andhenthat inarywo hogreaterhanastar.We natWerefore carefully Gntngulsh theapparent tetofanycjelromfsvealgreatness, iaalwaysananglegreateroFleas,acco paiedeieasl rae Gn tnessofthesunisanangleo Abouthalladegree,whereashisrealmagaitadfar that ofthe earth; forthe sun being ahisdiameterisestimatedtobe about 780,000 miles, while thediameter oftheearth is- iy7912 Engiish miles. Sh Jidy, 1700. LETTER XXXIV. OFtheAssistance which Judgment lends toVision WasrIhavenowsubmittedtoyouonthe sominon of"yonbelongs 10open,whichfas branch ofmixed mathematics, and which likewise Selea"coniderable "rankin"physis._ Besidescolar,thenatureofwhich1haveendeavoured oexplain,itithebusinessofopticstotreato Manneriwhichvisioniepertormod, andofthe diferentanglesunderwhichobjectsareseen. covenmumfaveaed remarted,tatesame jectmaybeviewed,sometimes undera ‘italangl,sometinea undersale,aistess ormore.distantfromus.Isay,further,thata 199 mur aserrance watcit oxen smallobjectmaybeviewedunderthesameangea8 Sireatbn,whetheformerieveryneat,arthe Iaforvery datant, "Asmall dish maybe placed tee *feelineyainsachamanoanocrethhel toy ofthesonyandyimreality,«plateofbala foot eampeter, athe’ cstance of24fet, exacySoreseansodeenenderhemunagefnd'el ataprodigious Serene here fwrecnthesizeofpateandhatoffhesum.Thgoathefantnofconsequence,noahasprest othesy ence,neniyst {houghrealymuchsmallerbuietobeconnie: frehattheaunealmoet400timesmoreremote‘fhevistatneftpointofwomuchthe ‘iaualengeapointofwomuchthemoreImportanceInopticmthatheimagesoftheobjectwitchpantthemselvesonthebatiomoftheeyeerent eerenehlka Minegreater or fect) aregreatCUMSAndwoweseothjectsottoFouedlver nly a0faranthelr images aspaiited onthe bot {on ofthe eye, ty constitute theimmosiate abject+ofvinionorseceation.One oftheseages,there-forelenevettheKnowledgeonlyofteethings:Piri itsfire and itncolours conduct tothe coe:Clitereotofnarochaf tach 2!Sgre, and such 4colour. iistagnitedediscoversthevisuangletnderwhichBelek sppec totoaotAllyn paceon thetotoDftheeyemakesusecoabieofthe AirectionoftheexternalobjectrelaivelytongoF thatinwhichtheraysemitedromireachoutoesteerepric omit tephenome nomofisonsaweonlyperesve,it,hegure tndcolours;alytheoadenc:teeppetertBape, antSayheGranorteHace tritchweconclade thattheobjectexiste:"Vision, Then,lacoverstousnothingrespectingeitherthe vem rom ‘tealmagnitude ofobjects,ortheirdistances.Though simpetnatae cea, Ta i enatetnncperaca ss Pee ce morte Re Sco te caningDictucn mannan eeeSimoessatan Wpeernc iar ites oe aan aie Panam eneSa seeSForempetgytthemaenomen pty ts trnaeng anogealtothatotthetere bodies which areseen under thesame angle, itis totbyvision they aredeceived, butbytheir judg- fier nne cures SOS ota ayeablecaseofamanbornblind,whoobtainedsight meneofanoperation, atanadvancedperiod‘ofBrat srnraaa oatofofetsAllobjects appeared90nearthatberuin them,AKcontenttimeandSoAeranenaSerthetermofchildhood, antofwhichweafterward poe|PSE aio sat enoneop Sere‘svpieal yeerosfafosas.p4e?-—Beaa 14 EXPLANATION: OFCERTAD Botefousomochthmorlaren dnsRismere,andreipocly, tatanectsek appears clear anddistinct isear; andwhen Wap FC'sthentetpainter,byweakeningthotatsofis than “ theobjectswhichtheywahwo remote, and +Hfengtheaing thoaewichtheywouldrepresentsx bourel credoubted todetereourjujpoeetcoo" formabiytotheeffectwhichtheymeanfoproduce ‘Andtheysoecco so"perfect thalmeona tomeoftheobjectsrepresented inpiningsxmoreAfsrntthanothers,anusonwhiccounottakePlaceifvisionGiocoveredt0uxthereldiatanceEnimagntade ofobjects: iatngurt,170, LETTER XXXV. Esplnaton ofcetcinPhenomenarelatingteOpieaaYettaJateenthationaloeinconesorthedistanceofobjects;andthatallweimagineSreswets asthedance ormaaltdeef tayobject ithefectofjudgment. “Wemast atefuly diainguisthatwhichthetemsenrepre sent0fromwhatjudgmentad,inwhichwe wwhobaredecaiadagainthescedacy'ofte Temes and who meant hence toinfer the ince taintyofallhumanknowledge, have‘confounded the representation ofourseaneswt ProRisietrmodeofreasoning:Weeeethewen tobiggerthan'strencher,ou1beinfinitelyfear tere hesenesofseeingdeceivesereforelloursensesdeceiveunalettwecal:notdependonthem;therefore,altheknowledge‘weacquire bymeans ofthesenses isuncertain, pesnounnaRELATIVETooFTICR198 todprobably false: we therefore know nothing.Sea'stheSeasoningoftheSkepicnwhotoa t>vsingloouslyoftheiringenuitythoughtere Fenotlag ooony unto enytat ery thi is Gia;thdtheresin unemaymakening fren thin tliepalosophy.” Bot1iabnoefinethatthenightrepresentstotheron tobiggerthanpewterplat’ideterminesnothing eter reapecting hismagne’ 1s outjvige EetneitSes Wenteha, wrever are not very distant, we eanwihtolerate exactoees ontherdimessionsana Extancen;andtheothersenses,joinedtothedegree Sfiearaces with which weaesthese sume object readerourdgmentssuficentycertain.”"Now, as toonaswehavetheideaofthedistanceofanobject, wreformtocursevenikewire thatofiarealtng? Tiude,knowing tatitdependa onthatdatance. Hoes,themotoistamwerockonanonjocttoy fhereser weconcinde inst magnitudes andre:Sirolseatrreonceithesar eesppoce.it We,ofcoure,frequentlytakeobeayBattierofnichresiagatewhen Socpeneion of uigaieat provects Our akingfanintotheaccount,“Thoreasonithat&eryliye body maybeseenatgreatdiiance,under fiteameangie tsasmalobjetplacednearom ‘hereinantherphesomenon‘walltownto averyone,andwhich’ha.givenoccasionfoa ‘Saputen Smong’ thelearned andwhichitis10%sanyospe lloonpears EitveryayesttheGimeofherrisingtobe!nl oYa‘whenabehagot10countersie above thehorizon though thevialangle ofteapparentmagntodsbetesame.Theeen, foo, atthe time ofsing and selng: appre 13 very oneqreaier than at'noon, “What thes iteSGonfation otthefgets univer ata fineTrinundoutedly becatewejudgethooun 6 ‘EXPLANATIONOFORRTADN semeneeingi siemens wnaerint‘Bathowcomewetoformsuchajudgment? Thecteenereetenerh tre recente trai betweenthemanduswhichseed!toincreasetheirEnacnelemareshoeee EEScublaiintatesuatoess Sairurtermmnat ore Ake aiseee eaeea epngteSasbeceathtameore Buen mecneemeine ieee GreeemiSaree hereSebnetnuas asternLemme AGthsearthyendthedeedcretetheSeSeifetationedatthePotAyifSamet brateee aeaemmeraaie 7sietedaaeons nts Bihrbagenteare Oflightwhichpasethrough«transparent mediumicherasmreatt Hatter teteraSeiiciractiname ircpraaan faceateSeyelenee stasabsgeenae? tialbodiesappearmuchleesbrilliantinthehorizon, PHENOMENA RELATIVE TO OPTICS. 137 eves ys ple ewtolookdirectlyevenatthegunwhenheisintheSeeayoeheeinee ‘ Pierehons aes Rope vrei‘SPpeare tousmoredistantwhenitelighttewoak- Rreaoeseyernyein likewise judgo hermagnitude greater. And ingen-Sieecktraor ir TorssualtotheangleOp,whicneiendealobecolo(Gromtabatogvoprond tbeatnachgratdasanee’Ween ‘Srecmed wobeSitwaybetweetheborintneteenh;DrSethSas sung|rags2 Fy i H i i i Le Ma se ‘oFsmApoW. LETTERXXXVIOFSain, Tavsendeavouredtoexplainalmostallthati¢ ‘usuallytreated ofinoptics. Allthatremainsiste spoutofado,Youareadyknowtoowalwhet ‘ismeantbyshadeorshadow, torenderitnecessaryformetoavelliongon themje.Shadowahfcpponesrothinsfumlootebayandoapease boywhich doesnot transolt.theraysoflight, ‘Theopaquebody,then,prevents theraysofalu-toedEadyfoxgetingTehthandtheapacetwhich tneray cantor rescefom hi interopTellineshadowofthoopaquebodysonwhatomentotetametng,saganciacethatSpaceinwhichthelfcbotyisotfobesee,Sishepeteboydaartybeta’lumigons Pew prac ———body.‘Drawtho:Pay ad BM, A DN, taalthBrensoeme mayer Acan intothe REDEDN,andinwintedorplatwithat theemaybepace9,forexmpl.twillst teethelasinousbody.Thispacetheshadow GFtheopaquebodyLadweeethatSoneiftheboytowswhichtsrayaproceedbsiteclf ofgreatmagnitude, thedetermination oftheshadow ormanor. vs issomewhat different. Therearethreecaseswhich stostodyleesthanibeopaque?ibesecond,whenSoanare tow omewehavenowbeenconsidering, inwhichthelightTanne comentPhe oreTore Fri re To. ymdntheerzomeye geek Dickies ae ccs peer teitesShceiieteeBESENaypes Pia new ;thelu eete inne iis,=n Fea|produced willmeet point-O,and{hespaceoftheshadowBOEbecomesfinite,andEse eteEhret ot parmaMotenhhkToa Mo (OF smapow. ‘noadmission,andinwhichitieimpossible tosee winehee Shere lotta reac eisSEEatAstetinyOw eet dts ies cc le rah ctamins aie arabana, omyieeetitra da ‘light ofthestin isexcluded. ERE eS ton or pe seta ite it meet lyPlungeintotheshadowoftheeartheitherpar Bee ee eeeae ei dieebierea aie Eee spawns “aoene aBehaotireeceaaearPet turmereaut Sine ieh mice ararertsStam cce,Aneta eee reed ‘butwearethenintheshadowoftheearth,wi Breech Hitherto we‘have considered only thecases in CEN get istic wgBecelid meeestom tresometimes reflected, tndsometimes brokenor Stararnin Biestateita came aereflected from thatsurface; andwhen they pass oroarorrmics 310. Mn fotonetransparent mediumtoanother,theyun-Aigoretectoa,andtreinsone.sonebokea,Heearsetwoothersciences.Thatwhichcontsopceaadthtwhichhanforieobjetvision i‘wl oritsobjectvision, isreferencetobrokenorrefractedraysstormed SepinasOpticstreatofvisionrelativelytodirect ‘pnotightshalpene youwih aunayteefoances cin ope{eydolonephenomens whichtreeverydaypre- teinthemed och iveimpose Tavetigatethechuseeandtheproperties.Ev Siering toheelectofionnyeyoud iosanobjecthighlyworthyofexcl ronty,tndofengegingseston, ad ihAsst, 170. LETTER XXXVIL Capris, ndtheefecion ofRaysfrompain hon raeofIntfallouwellolsed ay rays lig onawelttetheyagreeinucaannate‘gesonalsideaooqualamongthemselves.learigh,ot.AB, Fg. Figrie thevar. 5 of2common tnoutpoint howe oe aneae Pim,fallUpon the |mivor Ofallthese wichflapperSeuiarly on, "the ‘ror,vadwhichhasthisparticularandremarkable a oFcaTorrnice, ETC. property,thatitisreflectedupomitselfinthediree- Foror@ijrtaponabilan, whenthe isstrac iculartyagainsttheledge,itis balrkerlygeeee ray,asPM,isreflectedinthelineM'N,insucha mannerastomaketheangleAMNequaltothe ‘angleBMP;inwhichitintoberemarked, that therayPMisnamedtheincidentray,andMNtheFeflected ray. Inlike manner,totheincident Emwilcoregpondtheefeciedraymmiand consequently, becauseofthe.reflection,the.Ta PMiscontiauedinthedirectionofthelineMN, andtherayPminthedirectionofmm,20thatwe havetheangleAMNequaltoBMP.andthe angleAmnequaltotheangleBm.P.‘Thisprop- orgyithanoouncod’TheangleofreactionsheaysequaltheangeofincidenesThaelarony takennoticeofthiestrikingprop. +batmy ‘atpresentisto.showwi anteateseoseee Frehit'sevdentthataneyeplacedatNwillro. feeivefromtheluminouspointPthereflectedray MUN; thus the raywhich excites inthat eye the ‘sensation ofthebody from whence itproceededomeninthodirectionMN,JatsitheobjctP ‘wereinsomopointofthatline;henceitfollows{hattheeyemustseetheobjectPinthedirection Inordér themore clearlytoelucidatethisfact ‘wemusthaverecoursetogeometry; andyouwilleeolleet with pleasure thepropositions onwhichthefollowingreasoningiefounded,”Lettheperpen.dicularrayPeproducedontheothersidethe‘mirrortoR,80thatQRshallbeequaltoPQ;1 willshowyouthatallthereflectedraysMNand ‘mn,beingproducedbehindthemirror,mutmeet inthatolaFo,takingthetwoanglesP@i andBOM, theyhavefnthesideMQcommontoboth;thenthesideQRwasmadeequaltothe sidePQ;and,finally,theanglePQMbeingaright orcarorratcs, src. 14a itsadjacentangeRQMmosUkewiebea ‘angle(Huclid's Elements, Book1.Prop.13) reforethesetwotriangle,havingeacharequal tngcontin’tywoeaue,allbeevery swayequal(Euclid,BookI.Prop."s):and.conseGeniMeanieFMuaineangeiheangeAMCN,andtheangle1,beng vertical, areequal t0'each other (Euclid, Sook. Prop. 15); therefore also tho angleAM Nstall bevFiulotheangMQ!Heattheangle ofrofecton ‘ale equal10'sheangieofae relectedrtyim'mbeing’profucel, woul!ikaw mymm acedywould likewise ‘throughthepointRandconsequently produce EithoeyetesamefectasifibeebctFtereac. tuallyplacedbehindthemirroratRythispointbeing intheperpendicular P.Q fat thesame Gistanceas Pfron the surface ofthe mirror, but oneifferent fides. This will enable you tocomprehend clearly why” mirrore represent objects asifthey. wer®Dabindthem;andwhywojudgethattheseobjectsareplaced asfarbehind thesurface ofthe mirroras heyrealyaebeforeit.itisthusthatthemirror{Eetaporyobjectaterplace,witoutchangHeyWherappearance, fodtaguh otemaeparedobjectthemageandweeaytattheimages ‘objecttheimage,andwesaythattheimagesFopronoiad byredectedraysarebehindthear, isdenomination servesYodutinguahrealobjects fromtheimagesofthemrepresented inmirtors; andtheimageswhichweseeinmirrorsareper:feoegalandwinilar theob mththioeon tatwhatatesjet ontheehappear inthe image onthe right, andreciprocally ‘ThusPerson wearing hiswordontheeftaide,appears With itintheitror onhisight ‘From what has been said, isalways easy tosoftietheimageofanyobjectwhatever bebiadthe rror. ma aarureriin oF mvs ForA3,Fig.18,being 18,aninoaEPan nsShektay:anaro:eaeKmBGunHatothesrsoftnBian footEe hatte“qualtoe6,Teidheindeadapt hichwil1equate‘theobjectEF,becauseG2fitisinllreopocsequatothequndeatera treGEFH._Temuetboaullfrtnerremarked,tht ‘wereyouevanWocatoffromthemirrorspar,atGiantACwanthomiror,thetageefwouldbotbochanged”"Andcoussqconty,wnatemirror iota ingetatelingof PendiclareEGandFHuponit,wemust laneofthemirror‘obeextended,usweproduce inesingeometrywhenwewanttoletfallperpendic- ‘ularuponthem.Maeanaeefate lale, Seachmirers,whiseourhsBpare Soarerendcosstvemsavoreprodoe dereect, Thdupa,100. Lerrenxxxvm. Reflection ofRays Convex andConcave Mirrors.Pongror ‘Everythingrelat to-thereflectionofraysis seeteeheefonttengsteone ofwhichisthepaceofthmagewhichosreboctedraysrepresent; andtheethertherelation oftheTelogettheobject.Inordinaryoflinmirrors, oxanton us AegeoffceotithatSte oes het ta miraasaeaahaofheotrsmi icescelenimoeToShans Sromrieta Wasa= igaenagi iorgeen adYae it Bidet ary ptSe eeefeared ate 7ery sate,cormsoh SORA Sa Eel iereothgewellabsserineeantotie, Foc eo ce sepia agerromaler entre hyae totake awhole globe;anypartofitssurfacewhat- Sarokbesaofee denominated spherical; andtherearetwosortsofseioecong ieroaseeing Page abn on exe Fes as alts Sr ofrecemehceatPosafetygiih.erinof Sree! ay epee em beamirror,theseg- mentofasphere, man ots he |Ifyou place before Creal tors Eetance, hsage .dist»itsimagei 148 anrizcttoxornave thembror,atthepointD,themiddlepointof theradiosofthesphere©G;andthemagnitude ofthisimagewilbetothatoftheobjectinthe elationofthelinesCDand©E:itwillthere- feoininanomuchalethanibotastheing6Diaotmcksalehnthene ItheabjectBapproaches tothemirror,#0 Ukowiagwilitage”Thilldeponstae ongeometrical principio, any inelidaaywateveronyBsrectedinthedirectionofMN,20tbattheangleBMNmaybe‘equaltotheangioCME.‘Thu,whentheeyeis TN,receivingfheretectedrayMNyitwllveothe ‘ObjectE,accordingtothatdirection,and.willob-Soria,DwlbetheImageoftheobjectplaced E,butsmaller.“Itslikewisecaaytovec,thatthe‘snallertheaphereis,ofwhichtbemiror'ia8s0g-‘ment,themoreLikewieeistheimagediminished.Tproceedtoconeavemirror,theuseofwhichiaverycommononmanyoccasions, LetA.CByFig.20,boamir Mig30 Sreephere, thoesasphere,wi centreisG,andGCaratin, tatts=jeerede{2imagewillThaartestheIrroratD,themiddlepointoftheradiua©@;for SanolbatreyEMomthebjt fallingonthesurfaceofthemirroratthepoint TroughiepintDyadwhentheeyewplacaat Fntheoyeisplaced.a NritwileetheobjectatD;butthisimagewillbe 10theejectintheratioof©DtoCE,andconne-{jnrlyiniacaneemailerthanit.ABdwhenyou recat mnsees. ur ‘the nearertothemirror,theimagere-tettheoe!bgpncedevenatecee, teineterewise,Ifyoutigto ttlforwardtD,thimagewiretirefail SjondEe"butiftheobjectBeplacedsilfarther sewer Cae inewlanshod ‘Whenyoulookatyourselfinauchamirror,at sumeiteireen DtndGyoufacewilspearfaguibaly argos hs Ipexlaied bythefears tiotection, virtue ofwhich te tigi ofince ease8MKisLaysequatotheanglofref:tonGMN. Tothsspeciesmuabreferedburningmirrors,andeverysoncavemirrormaybeeitHiyed tobi, Ths remerhable propery tts Ties particular explanationTaABO,Higbbeaconcaveminor,whosecentreisG,andinsteadoftheob-Fig.91.ject,ef,thosunbeatBEhisreflected apewilypreeotthomagofeeuaDy'the.midale. pointbetweenCandG.ewthemarae ofthmagewilbe Maeraned itheexteme tye SC.86. ‘Thisimageofthesunwillbeaccordingly ‘eyenednalraytietak Iihlinage,theywilbecolectedthere, soleil bis womachesore fees; wesimageDlscmaiertanthosurfaceoftheTrithepropertyatbeatngthebodienon Whichtheyfall'swelasthatofilumingtingthem; enceiouowstattheremustbeatDafeatdes‘ofheat;andwhenthemirroris.sufficiently SipeaTheat may become stronger than themostre,infaebymeansofsachamiroryou tnayburinaniovagtanycombuatiblebody,Xd trenelttellsofeveryhind.Itsthoimage ow se ofthesan alone which produces these surprising ote gm i rots erg iSfos en ameFoescaydeepest aos fromburning-gleses, ofwhich|shallgivesomeac- LETTER XXXIX. OfDioptrica. Havorojined the principal phenomena ofiatitdara fier eeymeee Jectistounfoldthephenomena oftherefraction of ays,whichtakesplacewhentheypassthroughdif-ferent itmediums.—Arayoflightdoes ‘notpursue thesame straight line, itcontinuesah bir edEmenee, Ane ieee teres tae Ser micee mabe eee which itpursues arectilinear course, namely, whenitenterstheothermedium perpendicularly.Sr aes een dioptrics aretheglasses ‘intheconstruc- Sune waste cme efeieleeeu thing relatingto.themisreducibletothefigureof patemeteyereomentear eseedSiyerinGoesaneartumpes tim:Bd | or piorrnics. 49 smcave., Their convexity orconcavity isalwaysSeoaltothatofaephere,ofwhichtheFaiusmust SEnown,itbeing consideredasthemesureofthe carveofthosesurfaces. Thisbeinglaiddown,we ‘Madhavesoveralkindsofdioptriclasses Fig. 22 ‘Thefirstspecies,No.I.Fig.9,isthatwhosetwo faccaareplaly,Byeuiingfciealar poseoatOf&Plateofglaseofequalthickness,weshallhaveoneof Lisopedies which makes nochangeonobjectsether ato magutudeorditance, Glass No ILhasoneofitasurfacesplan,andtheotherconvexandancharetermedplano-conses.. ‘Thethitdepecies, NO-IIhas‘Sledplokecencene, Thetourth,NO.IV. hastwocone The fourth,No.TV.hastconetexeurfucen;andis calleddaleconces. Nov:bas {wo concave. surfaces, and iscalled doweconcoveThespeciesNos.VI.Vilhaveonesurfaceconvexandtheotter concave and wegive them thename. of ‘meniscus, “All these lenses are reducible twoClanees;theonecontainingthoseinwhichconvexityrevianon, VEtheother,conanty Predoizatnamely, NowlyVoVil forierclassissimply denominated convex, andthe Intterconcave. ‘Thesetwoclassesaredistinguished bythefollowing property.etABy Bbw¥converglansexponedto8 |gabepanepengthrougtyundergoartes {nthe gla,andpas ityundergoa Sabetvattepeeuchamanner,that 100 orbiorraice: fhe rays proceeding from the pointGFig.23° thalmect'ontheoeredeofte inthepits.Thesamehingwil Filloftbeobjecbytsaorta ofthoobject a EliteretracedraysA,Bim,Cmwil ‘ +praue thesame dredon athe objetWorele,gvfsandinverted,apdwl Eppesnimeet Se ‘iceCigthallbecontainedinthedi tanceCG:Wesay,then,thatsucha fase represents thesheet Fbehind it Ered thisrepresentation vealedndwith theobjecteli therato tage,andofteglamfftebjtcC Jct Rutlantheatitheeinwerehefoc ImageFopresented stefwouldbethaofthotan;thagheryamawilbo0brillantantoariatheeye,forallthoTayewhichpasehrowgh{heglaemeuinthisimage,andtheyexercitheseoulle power ofgiving ligt and heat. The heat‘ovianearlyusManynesgreaterasthewurfaceoftheglamexceedsimagnitadetheimageofthefindisJoeomwhichiftogbevryseespounyprotacethegroinetaofhes arable etetances plaedinthefocunofch gleretantconte"Metraein Eleveniniedbyandtoreectareprod [Erbyouttheechoftemosactivesnintense“ihereatonisthesameosinthecasoofburningmirrors"Inboth,theraysofthesundisedove{howholesurfaceoftemirororglassaecollectedinthesmallepaceofthesunimage,‘Theonly diftsreoceis,thatinmirrorsthereyserecollected tyoection,andinglanonbyrefraction. Suchin or ponmo-ouasrs wt theeffectofconvexglasses, whicharethickerintheSasageestame chancekere, Bent lettbetStebelUnterietorsconcave,producesconeebret,aaChiyattadicothsirn yyWUE RathoreERGee,osc rath Fshweo‘arefraction,onleavingtheglass Hintheduotecomtepomtgrand\f seeeomenrae:td RezotesSai eaSeer ree i aot eee ee ecageat ‘averydistantobjectbehindthemcon. srrydinaoesihece Fath eoongr arte Nae ataacehanksae an act ao eno nee Eyeee eee eaeeenestadice |Continuation—Of Burning-glastes andtheirFocus. Convex glasses furnish some further remarks, ATifarelaybigeyeopts ‘ofthoseglassesingeneralwhicharethickerinthe or poummeatunedehnteres reef iesenoetri)iterahencom oebassecre vided,however,thattheconvexityexceedthecon- SiegNene sae Pye eatilybaatpyserineeeeoatneort heeydtmtenon iheeeofdateaerhbnone ing.Thereasonis,thatalltheraysissuing fromineyaleeee thereffactionoftheglassintoasinglepoint.‘The aeae aee tea,ae eee, oeNSonacatewoeTem Bonmiawomer greenest Pigg hetnphytate eeonomentecre ASacecoteSePegsEe pl ie mnacoeee sarheYiealoe BCcmltatrefractioninthespaceAgB,andmeet Ripsnee Agewen ‘thepointF,whichfallontheglassin theangleAFB,arerefractedsoato PeeAemeetinBecine/,Dacateman ‘theglass;andaneyeplacedatO,behindtheimage, orvoumecusne, 188 iliehanymemet atesneatWinedisidiceDpisamalorhanedistancoC Gy Sear memens inerteyofmeee beremarked, thatthemoreconvextheglassis,in GBreoticotePaPleeeseer peor aeElmar ca Cte inagetethenthesatedianeaxhaofbwuor‘thelens.When theobject,then,is distant,iyehhtresalee ‘bring the object tothe glass, the farther theFee tofanctr determinetheplaceoftheimageforeverydistanceioae ie meamereglass,thatis,thedistance atwhichitcollects thefit ryoNarttd Ti Ade Aweeps weipgoviian Segene ghpesoftineNy,fe Sart pre Tiratmt iatofdeyyafe ce syrechadis hheoaedtsoft focus,anditisextremely dificulttomakethemexact.Ioncepaid150crownsforonelens,which Teoni totheacademyofPetersburg; ithasits tn sravezames, focusatthedistance of600feet.*IamconvincedRe a ttthaywishedtoans 1Seematert Fe TI, vepreentaion ofthefostinRiierolyouhategayte holdwtthatplace'spieceofwhitepaperthepar Teelteeaaneateras Sener ek Pee sent Phen a tivepointwilytheperceofthepapents eearenes.EontentofatinarttaichthePorthosemecolourtothepontE-InlkefoamfonpinsfaantaethesanecoursestepeGF cesanYouwa oetoeoapapeaoepotetheeect TeeeettsRabeot lect Seencaeee:Secaeee Sieet,Tis mrtprety wa ce PeteBaeintheserYouwiltheneonsheet, Sangaatenecatanett Sheanalltheexternalobjects.96° painted,thatyoumaytracethemwitha ndatyumee 2 Jandscapesandotherviews.t i Lagu, 0. apappeepomsiareas BetbtSESSECBugnttmentyceeeS whoseae Sone ees See eee eee eensoe Sal meoes BySee areaResSES mretomemeeoe8, | oFvisto. 158 LETTER XL. OfVision,andtheStructure oftheBye.|ltaosotoJxntebenomeofritcndocteiy oneStineprone Uperationsofnaturethatthehumanmindcaneon:Prat ebbeet" "he lerredo ierGree SeateleconcoeaSe |foweranl'winn ofthe Genin. Wegurorer a |thestractreoftheeyeperfectionswhichthemostshallnotdetainyouatpresentwithananatomi- caldescription oftheeyerItissufficient10reapenneetet,Eeceretesn meeealagetylaa| Seeahelrcmton ofeychyomatermcoer,Shee eredeere branchofSpetaybe?Se Starrs me seeps mga PeeSe tee al aero Seti eeeEienbeanieeaece Eup ree onnnansss eeinno ty Sreeaerate canoe ee erratesaie SS eevee ae Sc caantemcsBeeelasgoitenpnta9-8‘ond atngappro os tscrvaemttetoenetpadiecalledthecometofaEhitinraesoee SNSrmenmncear Se» ¥mycircalar andcoloured,which*\(@Wy aisiemeaeeSacaereenseee eryBie AST Bean anaye eat artme aSY Sri gieeeeanneSey ocean Temes Fesate emerpeceo fiaSaahhemianhicmt ae at Seeemartnen aeekpeIAMa Zethanpan:Itheanteriorcoatorcarne;3 Sete eekSthieee Eereeertieteeneicat Saeeee tngtee artiBaraleaare BeeereseesIara SeiaetatParaabet sertieAPpatRecieemttegenaon furnishedwithawhitishtissue,adaptedtothere- soe ne atea einai a aha ape Bemahaciaienaiae cee wertce SeSark eaweeae ! ermvcruke oF THE EYE. 1st theresoexactlythatnoartistcould Meerarestiveatuck'egrasofpocoebon, ‘Andinordertoseeanyobjectwhatever,theobjectimustalwaysbepaintedonthoretina;andwhen, unfortunately, anyofthepartsoftheeyearein: {feerorlsetei transparency,theporsonbecomes ‘Butitisnotsufficient,inordertooursocingob- Jects,thattheirimagesshouldbepaintedonthere- tina;someareblind,thoughthistakesplace.Hence weseethatimages paintedontherelinaarenot, afterall,theimmediate objectofvision,andthat theperceptionofthesouliscommunicated some otherway.‘Theretinaisareticulated contexture ofnerves themost subtle, commanicating witha {pestnore,which,Comingfromthobrienters fheeyeat0.andisdenominated theopticnerve. ‘Thenpallerrsoftheretinaaegta bythe raysoflightwhichformtheimageatthebottomoftheeye;andthisagitationistransinitted bytheoptic [email protected],undoubtedly, that ‘meatalperceptionisformed;butthemostdexterous anatomistisunabletopursuethesenervestotheir touree—the unionofthesoulwiththebodymast forever remain amystery. 1hAugust, 1780. LETTER XLII. Continuation. Wonders discoverable intheStructureoftheBye. Izwillnotbe disagreeabletoyou,Ihope,tocon- templatewithmersSmcwhat mreettonvely. te ‘wonders discoverable inthestructure oftheeye. _Apatest"thepuppresents anobjecthigily wolthy ofadmiration. Ttisthat aperture whichwo findinthemiddieoftheirisorstarmm,bywhich Vou. 10 1 saat 3ome:=etneoveadich n- ~ Sa ee if WL Fem onen TSTassSeretsHt - SaFeTeicaths : _ + ree * ol TEhess be aes te2 ERS f LRAT br 7 US th (Sees ey . esfen wsPri “isa - wh eravervns on ome are, 168 Westinouportopethepptnore weahouldbeabletoseinagreaterdegreeofdank-eno iepeore ee tonYessodatedbyithathecouldreadSaddal, Guish theminutest objects inthedark. Cats, and fperas weounc hvelyostteflachosek thehuaspeciesadowshavetheraaltimex melated tobear even amoderate degree of hontepplofthhumanegaeot contac isnot" anactofthe wil,mannot Siig hepower ofSing’ ofeng Se Palle eave” Reson ke sour aah Ba an, iohne corey ad Eaton en Paaee e aeie-notproduced inaninstant; itrequires alle ‘hari Spaceman Fad ‘You must, nodoubt, have remarked, that asoftenweyoumalescoyeelCasakontetarHel ltdadpace Seheat fuceratatala SpayBe Ta sal Gene, MonseesWhichitadmitted tomakeasensible impressionGTpeeanagealy denlyfromdarkness toeclearightPhepopil beingthenverymuchexpand,theretinairack ina Livelymanner, you arequite dazzled, and under Bascal ofthe ope ih everyrene chumatacy Dat tap Shad Eile an onc cag Meera nl a tye Soa ls «pen. er tr tmnt ett Seeser ea 160 WONDERS INTHE place almost epostancouly wd independent ofaweserraensray, tdidepenieay 2 Reteaulecnpehecame genaseSata wane”a 1etea a aeeereearet ‘Thevariabilityofthepupilis,however,anobject eyaayata SSRINeyalge Baetna ticularsarediscoverable,equallyentitledtoi rasaga, 1780. verrexu. FatherCotton—Arence MiaByeofenAnasendthertfoedByeCorePaee ‘Tu ‘ipleonwhichthestructureoftheeyeis colinringl ouchhedroinsee whichIexplainedtherepresentation ofohigetson in Lexiethromanaofogiot errsetmi seeeeiaaoeTeEollectedinasinglepoutbyrefraction; andsessetipa wtwiaionpe rach eary see cane fultanctsofwhichtneeyeicososed.“Trent creainferredfromnetcyhat8strcturemore sennaieamen,aetaore transparent substance,wouldhavebeenproductiveSaar eS Seaton Siac agi oe Seer teenFT artte ld sraverens oF Tmt eve. 161 Creator, who has assuredly pursued the simplestfoudinibeformationofaltisworks.ersone haveaotbeenwaning who,romnot having altentively examined theadvantages real tgfomthiapparent complain, presamed to ‘censure this beautiful production of’the Supreme Seing witha levity worthy ofcensure. "They havepretendedicwasintheirpowertoproduceplanImore simple Yorthestricture oftheeye, because they were ignorant ofallthe fonctions which that arahad26icharge, Talexamine tila their; andThopofoconvinceyouthatitwould behighlydefective, and.altogetver unworthy of Ding ‘poincompetition with tat which tually Sachaneyetherefore,wouldbereedto2 simpleconverleas,ABCD,Fg.2,whi collects, inapointyaltherayscoming fromF&27-feandthemimecorreponding pointiatheREthininonlyneartothetruth.The spherical form given tothe surfaces ofa idns islable to"this inconvenience, that it does otcompletely collet inoneandthe fame point therayy which passthrough its fcentre andthose which pass through isex- Eee Thereaavaye alier ‘ance, though almostimpereeptile, in‘experiments, bymeansofwhich wereceive fhe imageon©pceofwhitepaper,butif {hishappenedintheeyeettwouldrendervision"hepersonstowhomIhaveboonallrecstowhomIhavbeen; tuntybepeaoeanteureftiagnoftheem:hichstallhavethepropery fcollecting anewalltheraysissuingfromthepoint ©inpot heer theypathrou thefcéatteofthrough“theextremitice. Iadmitthat{Sittaybepon;butsponheenopee . 168 WONDERS INTHE seesthis with tothepointO,atthesree, tleralfeeds00epee r afb aucfomet SRSete ei ie reew ea nt ey stance. Accordingly wesee,whenobjects arere-soderaeenceriney imertclnvir enemamh eee anan rerperp trrhteSopcieenhatienciaeca tenynceSeee eesiete eneceee= ee JensAB.werecollectedat’thepoint',thissrould betheplaceoftheredimage.Butifthepoint0 ‘werewolet,theTayswouldbocollected nearerto‘thelens,atV.Again,aswhiteisanassemblageof Bile2,Agimheacaof SiStcrkee cramerrealioecongewia ieSeeeereg)aeco roomtheexternal objects arerepresented onwhite mimeeweeereBauertlrt encase ee si pm_WemFewledsthathiemaybodonebymeansof eerm mayenmamact intupchtheez orneer credgesee ee sravcrons or Te ars. 163 But the eye which theCreator has formedisub- {ectotodofalheImperfections derwhichImaginaryconstruction ofthereethinkerlabours,domhasemployedseveralranparea wbetancesinemployed sev ubtances in{heformation‘oftheeye,itistherebysecured anitall-the defects whichcharacterian every work ofman. What anoble subject ofcontem- Faton! Howprtinent thatgorston ofthePuanIRFeleYormedheealoter}onde ttlplantedthecar,shalHeathear?"Pheeyealone Bring©masterpiece thatfartranscendsthohuman‘deratandng witanexalted oemmasweform‘OfHimwhohanbestowedthinwonderfaliyand ‘hatin thehighest perfection, notonman Galy, but ‘onthe brite creation, nay,on thevilest ofinsects! 11h Auguct, 1700. LETTER XLIV. Perfoctons discoveraie intheStructure oftheBye. ‘Tuseye,then,infinitel ever sceofsechaniam whichhumanakiscapableofpro- ‘Gucing.Thodiferent transparent. substances of ‘whieh tis composed have notonly depres ofden-Sitycapableofcausing different refractions,buttheir Spee twine detrmined iachenaier, tat aysproceeding fromonepointaftheobo teeealZaleciedin‘oneendthe:samepets ethoshatobecbemoreewdtswether bo situated directly orobliquely with respect to the‘oye,andthoughsnaundergoire Wierhelastchangotobemadinthenature apdfigureofthesesbstances,theeyewouldoweB's "vantages which,wehaveeensdmising‘Thestrength ofoursightisexactlyproportioned to 164 eruvcrons oF mx rE. theextentofournecessities; andfarfromcom-dngnatobjects100remoieeacape tisgen,easly onineonrary, tocome oneofiEiiarecongiofiheSupremeBae imustbefirtberremarked,thatinordertosee saeco entthatteaye switchcomefromone’pointshoalbecollectedia Toten"iintewsnecnny thheponof uninshoulfalpreciselyontheretina:ifel therebortof orBeyond 4vistowouldbecome onfanea. ‘Now, ifforacertain datance ofobjects{iopountofonionfaupontheretinthoesof ortdnaotswoullonsparwithathe Gyefthera:ndtvofnarerject ‘wouldfal!beyondtheeye.Ineithercasethere ealfeCaton‘teimagepitiedonthe ri, "The eyes ofevery man therefor, areconstructed foracerts Gntance.” Some persons seditincllyfischletaarewrymereteape,homMjopr,tattnshore-ighted.Otherson thecontrarytamedPresiyte,atdinelyobjoctefly which arevery Sista” “And those who geoSintinetyobjctaatmoderatedistancearesuidto havegodevee.”Bothhovetwohoweverhave thepowerofcontracting oFdilatingtheglobeOfthe yertoacertain degree, sadthereby ofbringing Bearer, orofremoving, the Tetinn, which enablesthemlikenswo‘clearlybieitemoreor thi,retell contr{CrendertoeyemoreperoelabitSantsorelyBeerediodancemerely .‘ThowewhohavegoodeyesGeivemostavant fromtheisrocture,astheyaretusnscondition __toee Gtinlly object very distant andverynea! butthisneverexteeds8certainnt"Theres,perhapsnoonewhocanseedistinctlyattheis, :Exnce'ofanSachan,conmguenty, illles’ata |or oni, 10s smallerdtanoe,Ifyouboldpoeofwangclosetooureyes,youtwiloethecharactersbut sensokney3heapesefooro eat ofsuch igh porta? Sid ag. Lerter xy, 0Oasis osoerPropertyofBoy Hara sow trae oflitt proceed tothe canieatn osproperty Connon. ber feorrr Wetaafose,oita ‘fluid,falldownward whentheyarenotsupported. ecientarteedenPa Fortra ertad ‘ibamineconteofnatetenapreefneying Seertrmmeedribetll peeshe {algeoenoepaydiyetanayant ‘Soadatdbown aSoe,"Tneeepctharaincome Seeaeis,Somesemee EeeS Taepietyemcee eefeaeseaaea erentetaqistinorices Maaraneeae ‘Gevtsees hemoer,bedcaexpenthereinteene abdmrieatonoftheUndernhe,hepltecoreaad‘falposeovinemechanisthtebru9peooram, ebSeon camachkaos ha pee TEE Samsree 180 onavrre conutpxazp As holdastoneinmyhand;ifTletitgo,itfallsto {heground,andwouldfalstilfarthetwerethere aitheearth.WhileIwritermypaper ‘wouldfaltothegroundwereitnotsupportedby Thetable.‘The:stinelawapplies,toeverybodywithwhichweareacquainted. “ThereiaHotoneThatwouldotfallothegroundiftwerenotsup.Potted onsloped bythewayheauthephenomenon orofhisprope: sityofallbodies,iSenominatedgrewty. Wheni istidthatbodiesareheavy,orpossesgravity,we‘eanthattheyhaveapropenaitytofalldownward, toastay wold weromove whatbors"Rieancientsrereiteacquaintedwiththisrop-. ergTingtele iattorworetealJue;adsuchbocatheytermedgh0dae andauchbodieatheytermedlight,to Tinguishthemfromthosewhichhaveatendency to fat Datthas been discoveredyexperimentoat itistheairwhichralestheseeubatancesaloftfor Inapacevoilaatwellknown,bymeas Dotthelairpump,thatsmokeandvapours descendas srellas stone,andthatthesesubatanceeare,oftheir Don nature heavy, like others. “When, therefore,{heyriseintothear,thesamelawactauponthem‘whieh actaupon alogofwood plunged into the Mate, "Normhanlng 1gral spans opsoonayoueaettsteladtri,Decneisnotcoheneyauwater;andinvirtueof geoe- ralrule,albodlestiefiafuldofmoregravity{BEyoutowpeoofiro,ofcope,of pieceofironofcopper,ofsilver, apdevenofled,itoveaselfulofyetkelverthey Swimonthesurface;andifyouforcethemdown : they reascend when ieft tothemselves. Gold aloattink,becauseifsheavierthanquicksilver.” And+Poiee sic yy rt Forthemercurychebarometer,“When,tee. Femightbeobjectedtothisgeneralpropertyof spre Maattions raemet Eeis ier aosaaaes peothattheymayberowla,Dthi biti eral a cara setieirssineramar aaa semana areas aie uence 168 OFSPECIFIC GRAVITY.esateamiahaneineLt STEei caeyarpaidghteat ieh nae a Se.hreaedieossee eeleySenet cremetomen.Abodylikethiswould notfalldown-‘ward,thoughthefloorweresuddenlytoberemovedoar eyrere emtTike yetetnneegeometetch srcapermye Tebor giescrrict arahveYaa eran see gereed‘88dAugust,1760. barren sure Continuation. OfSpecificGravity.vosmeteneentatgiesetpopmatinarieeopro cyaa ih ree awttenpnereeara pier= ence vaenSee tiestyeee seer ibrpntofole,pedo tod den“reermprett,ihc ee ctrenmnanememenyaaa venues orsrxcmeonaviry. 169 tody,oi texiats without i,sothatwerethisex- ttnslepowertofilinitsoperation,thebodywould teasetobeheary. Beforeweattempt asoltion of thissitwilbenecessarytoexaminemorecarefullyAllthe circumstances counected with gravy."remark, frstthatwhenyousupport. bodytoprovent itsfaling,iftreatsontableitspressureFrequaltotheforcewithwhichitwouldongtofll anda thread fsafixed toibywhich itmaybe faspended,thothreadisstretchedbythatforee;in ‘otherwords,bythegravity ofthatbody;sothat,if thethread were notofacertain strength, itwould break. We see, then, that allbodies exercise a degreoffnathechatswhichsupporthem,Prsrentier ling adtatheaton inpre‘nelythesameasthatwhichwouldmakethebod} devcend ititwereatiberty., Whenasoneislaid ‘pon atable, thetable ispressed byit. You have irtoputyourhandbelweenthestoneandthe {abletobesonableoftisforee,whiehmaybeinteamed toauch adegree asevento crush thehand. ‘This foree iscalled thegravity ofthebody andit isclear that the weight orthegravity ofevery body signifies thesame thing, both denoting the force with which thatbody "spressed downward,Srfetorthisforeexiststnthebodytnelorout ‘We have anideaooclearoftheweightofbodies, tomatoomceasryo dreilongr ontheweet oniremark, hatwhentobaiearefinedoe ster,theirweighttooaadded,sothattheweight ‘8Fthecompound isequaltothesumoftheweight ‘oftheparts Fromthisweseethattheweight ‘Ofbodice may bevery diferent Wehave aso the fertain means ofexattly measuring andcomparing thembytheofnance,whihasheprope frtyofrestinginequilibrium, whenthebodies, instwoscale,groofequalgravity.” taorgawo ‘akethcompton, wengeson sieodmew. ou 170 (OF SPECIFIC GRAVITY. ‘surement, ofacertain determinate weight, suchas8pound,and,bymeansofagoodbalance, allbodiesmaybe sodthergravityasertainod,ae- ‘cordingYothenumberofichtheycontain. ‘bodytoogreattobeputintothescaleofbalance inaybediviled,andthopartebeingveigiedspe.rately,youhaveonlytoaddthepartic‘weightofawholehouse,howeverlarge,maybetonrccastnodoubt,havfrequentlyremarked, fouasl,90 2 iy thatamallpieceofgoldweighsesmuchasapiece ofwoodgreatlysuperioriseaprofthattegravyofdiesnotaayasoplatedtytet Iapitode:"a‘eryamall‘olymaybeofgreat ‘weight,whileaverylargeonemaybelight.Every iy,then, mnepte oftwo meanurementaen .Ltrelydiferentfrom‘eachother.‘Theonedeter. ‘minesitsmagnitude orextent,calledlikewise its ‘Sze;this‘measurement belongstotheprovince ofgeometry,whichteachesthemethodofmeasuringthemagnitudeorextentofbodies.‘Thothermode ofmetvarement, bywhichtheweightiydeter ‘mined,intotalydiffrent,andservestodistinguish tBetalaeofthedifereatsubstancesofwhichbeciee ‘Youcaneasilyconceiveseveralmassesofdiffer.. ‘entsubstances, allofthesamemagnitude orextent; cachorexampleof&cubicSure,whoselength, breadth‘andheightshallbeafoot.‘Suchamass, iitbeofgoldswonldweigh1390poundsifofsilver,70pounds}ifofiron,800pounds,andifof ‘rater,only70pounds.wereitofair,itwouldweigh tnomore.than thetwelNh part of«pound. Prom{hisyouseethatthediffrentsubstancesofwhich bodiesarecomposed vary‘considerably inrespect terms,whichmightappenrequivocaltheywere ;‘which wereorporeclyuileniooa, ‘Thunwheni'lSad, anusartativeToonary,171 hatgoldsheavierthansnritiottobeunder: ‘2poundofgoldisheavierthana stilver;fora,poundofwhateveraubstaica is awaysapound,ahdhsalwaysprecisely thsameSeipfrthemeaningotthavingtromasses Ofthesamesizo,theonegoldandtheothersilver,theweight ofthemass ofgold willexceed that of thelve." AndwhenitIaidthatgoldis10 times heavier than water, wemean, that having two ‘equalmasses,theoneof21,theotherofwater, that which isofgold will have19times theweight ‘ofthat which isOfwater. When wethus express arecres, wesynotingoftheabeolte weight‘ofbodies,weonlyspeakbywayofcomfindwithreferenceziwaystomassesofanequal ge,Nair ofimpurtancwhether the tae Sisagan 0? ee LETTER XLVI. ‘TermsrelativetoGravity,andtheirtrueImport Gnavrrr, orweight, seems s0essential 10.the natureofbodies,thatitiselmostimpossibletoform theideaofabodydivestedofthisquality.Anditeinfluenceis#0universalinallouroperations ‘uponbody,thatwemustineveryinstancepayattention12.gravity oFweight. “Astoourbwnpersons whether westand, sit,orlie,wecontinuallyfee theeffectofthegravityofourownbody:wecould |neverfallifthebodywerenot,aswellasallits artsendowed withthiforce. Language elfiregulatedaccordingtothispropertyofbodies.The placetowardswhichabodytendsinitsdescentwe termiowandtheoppositedirectionfrmthebody wweterm high.1smustberemarked, thatwhenabody,infalling, 1a emss ssi eure, chp ercerat wards.. Thislineislikewise calledvertical,bywhich TeeoeiiegamTaecaaaiek ton . ERNIE Lie eeeSeteiehere genialoa Ehceh creer aethat otke esi, Se ieee aseay ere ‘be stretched ont intoastraightline,andthat mbenerarea eectae ‘ithleadenballstoneond,writentheycall= ‘plummet, todirecttheperpendicularityofthewalls fersco ernest Lo Tie rr uh oe ret a a She nae el gerisacyorerintacan Sch tae ets cl erie San rrgues fne Cay - Samet URgdbaya ustrte haan ost ie St ae EneRahaomenvi iloamSeayteesnceearanna mayen aiepuorks wearincarihee ich aia re rete Refine Strela. ga 4 aL ia ec an ne pons AND THEIR TRUE DXPeRT. 173 stagnant,andrmdownnolonger,whereasallrivers trecontinually fowingtowardsplaceslosselevated. ‘Thereareinstruments bymoans ofwhich wecan ascertain whether two points areonthesame level, ‘orwhich isthehigher, and byhow much, ‘This instrument iscalledaevel,andtheapplication ofi& iscalledtheartoflevelling.‘Wereyoutodrawastraightlinofromanypoint inyourapartment atBerlintoagivenpointinyourapartment atMagdeburg, you might, bymeans of such aninstrument, ascertain whether this line were horizontal orwhetheroneofthesepointsweremore orless elevated than the other. I believe the pointStBerlinwouldbemoreelevated thanthatatbfag- eburg: andIfoundthisopiniononthecourseof theriversSprée,Havel,andElbe.AstheSprée‘ieotheHaveltientofourbehigher and, forthe same reason, the Elbe must be lowerthantheHavel:Bevinthereforestandshighertan Magdeburg, provided youcompare two pointsatan* qualdeqees ofelevation fromtheground; for ‘Were astraight line tobedrawn from thostreet pavement. atBerlin tothepinnacle over thedome HtMagdeburg, that line would pethaps behori- 7lenceyouseehowusefultheartoftakinglevelsinwhentheconductingofwatericonceae.Pot agwatercanrunonlyfromamoreto.lesselevated‘situation, beforo diggingacanalyoumustbewell ‘soured that one ofthe extremities ismore elevatedhantheother,andthisdiscoveredbytakingthe ‘Inbuildingacity,thestreetsshouldbe20dis- osed,asthat,bymeansofadeclivityononeside, thewatermayrunoff.Itisotherwise inthecon- struction ofhouses, thfoorsofwhichshoul beperfectlyhorizontal, andwithoutthesmallestdecliv-Fry,because there isnowater tobedischarged, ex-cptinthedoorofstables,whicharoconstructed 174 nerty fo centam onrecrions withagentledeclivity. Astronomers takegreatpaki Sc eneroteart iyleveltocorrespond withtherelhoriod in the heavens. ‘The vertical line, produced upward, marks the zenith.SHAAugust,1700, LETTER XLVI. Replytocertain ObjectionstotheEarth'sSpherical"FguralerteedJoonGoenly.Youknowwell,thatthofigureoftheearthisnearlythatof.globe,Tthasindeed,beendemon. strated, thatitsformisnotperfectly spherical, but ‘somewhat fattened towards thepoles. The difer-fence,however,issotrifing,thatitdoesnotatall affecttheobject Ihave inview. Neither does thedifferenceofmountainandvalleyexciteanysolidobjection toitsglobular figure; foritsdiameter being7012Engle ‘mienthhighest mountainabeing about fiveEnglish milesinheight,sinkinto nothing,compared tothisprodigious mass. "The: ancients hadaveryimperfectnotionofthe roaligureoftheearth.htwasingeneralconsi asahugemassysubstance, 98, 23CD,Figs96,fattenedabove4 asA.B, and covered parly withertpariwithwater.ho.Goringotheratherac, A.Balonewashabitable;anditwasimpossible to jobeyond thepointsAandB,whichtheyconsid redastheextremities oftheworld.-When,intherogreas ofdiscovery, itwasfoundthatthe earth‘wasnoarlyspherical,anduniversally habitable,20{hatthere"wereupontheglobeapsdametrically‘oppositetous,heinhabitants ofwhicharethere-forecalledourantipodes,becausotheirfeetare yo mE rari’? wioURE. 170 tameddirectlytowardeours—this opinionmetwith tochviolent contradietion, thatcertain fathers of ihechurch represented itasadreadful heresy, andthunderedoutanathemasagainsalwhobelievedin UheTexisieaceoftheation, Aman however would:nowpassforanidiotwhowouldcalltinquestion especialyncetheopinionhisbonon. medbytheexperienceofnavigators,whohave frequentlysaldroundtheibe Butsterdf fealtyhere.presentsitselfthesolutionofwhich must assist usindiscoveringtherealdirectionof eamiy.Te'thocircleAB,Fig.20,saythey, representecartariwoareatky78,99. ‘urantipodenwilbediametricallyop” ositeafB,Anwe,then,have thohead pwardandthefeetcownward,ouran- tpodesmusthavethefeeupwardand thehead downward, supposing thesewords toindicate the sane direction Zi'when we prononnce the same words atthe place where we are. Foravigsor whohavemadethcircaofthoglobe,obnervahtheirheadand feothadthroughout. maintained thesame_positionTelatiely tothe surface ofthe terrestnal globe. ‘Some persons, whom this phenomenon ‘embar-ratedformertoughtofexpunge com. Furia of'aglobesertheturface-of which youfeefiesandotherinsectscrawlontheunde?as ‘wellastheupperpart.Buttheydidnotconsider thattheinsectaonthedependentsurfaceadhereta iebytheirclaws,andwithoutthisassistancewould :ilyfalloff‘Theantipode, then,musthave Fischoesurnishedwithhookstoholdhimfasothe ‘surfaceoftheearth;butthough hehasnone,he doesnotfall,anymorethanwedo.Besides,asweim agineourselves tobeontheuppermost surfaceofthd tte mae pmncran earth, theantipodehasthesameideaofhissitua- shoicteeence es omed sist preheat sa Se giaeie Bia cen,erete,alee guardaoddoemeerd,thereforer donotexpresat meses Pre irae itn, but con ofdeorergenyihren aea‘position whichthepowerofgravityconstrains themspinesajareyae tepeti ppleeitsclerotic Yui eos anditisnotlongelapeed,whenitwouldhavebeen. feosengcprie, et Someree 98hAugust,1760. erren xin ‘TrueDirectionandActionofGrontyrelativelytothe ‘Tuovon thesurface oftheearthisunequal, be-ferris aseborat ii ieee greatfotthevera!line,inthedrectionofwhichbodies‘fall,beingperpendicular toit.If,then,thewhole iSingeyi, wi Sireerele seiSmee aere vent wert, ! zontal;atA'theline«A fedEartcre ordownward ;topersonsat. :Kieeraktntward,andthepoint«Dytetsicheratterae ihe faa alien taeitech teeter BeeATAGettoaaeracaa Bett Aculet hccatimtie mics sa ca temeealotdorirate fomtheearth:ad,universally,menhavingtheir Feingproduceinwardly,wouldmeetatthecontre Bs paradiseat feattaneaeore FeripectShade 178 ACTION OFORAVITY.thesarwermutbewhtaproscosoarste sureoftheentinheyeregow100¢fateinteearthatwhateverpiace,andtocootsue Leduuwowardperperculasys Youwoulaeat at: eachbecouseeflbecart’.Youwilremocter KevYateone0nighattheeaof«Bae Teachingfothecentreoftheearth,mentionedby ‘Moupertar Itivtroe,suchaprojectcouldneve beexecuted, asitwouldbenecessary todigtotheGepthof080Englishmilee;butthreiuoharmSnbopposingit,inordertodacoverwhatwouldbeMatuseappcee,then,sch =then,suchaFig.31. hole,Fig.31,toatA, tatconfanedbeyondfheoon?._Heoftheearth0,thewholeJengthofthediameter,asfaras. sworetodobcentalhagiswpe wereTiresBeforeamg: tho gicyaavgFasc centrofinea?OwilterePipaandslowsometingmpportad : sy we ouldfalltowardsO.Duthavingpasscdbeyond thecentre,toF,forexampleourgravitywould(hen havoatendencytowards0)thispoiutandmuch morethepoiatA,wouldappeardownward,andthepointBopward."TThus theformeupwardanddown Ward would. suddenly change thei signification,though'weshouldhavepassedfromAtoByinhedirection ofastraight line,ihlongasweasonthepassageromAtoO,wearedescending ;butingoingfromOtoB,weareSctoallyrngforweaterethovingfromtecentsOftheearth—ourowngravitybeingalwaysdirected towardsthatpoint;so'thatifwewerefofall,whe- Action oF onavrry. 170 |theefromEorfromF,weshouldalwaysfall1o-‘wardsthecentreoftheearth.OurantipodeatB,ihewantedtopassfromBtoA,wouldbeinpre: cisely thesame situation. From’ tothecentre ©hhewouldhavetodescend;butfromOtoAitwould heallanasceat,”Theseconsiderations leadunthus {0definegravityorweight:Itisapowerbywhich {ibodioeareforcedtowardsthecentreoftheearth.‘The eame body which, being atA,isforced inthedirectionAyIftransported toB,willbeforced,by‘thopower ofgravity, inthe direction BO, which Airey gppoate otheother. Bythedtection ofsavy, then,weeverywhere ropa hesigna. fonofthetermsupwardanddownoard,riseand‘de-send, a3gravity orweight hasavery cosential in-ffuenceonallouroperationsandenterprives, andas evenourownbodiesareanimatedbyt10such ‘ogresasuniversally tofeeitseffects. ‘oth August, 1700, LETTER L. ferentActionofGravitywithrespecttocertain PGiendDeansomtheCortheEarth ‘You aro now sensible thit allbodies are forcedaizolytowardsthocentreoftheertandper~ endictlarly toitswrface,bytheirgravity:‘the Femondicalr aesahesurticeofspake sre Eecordinglyconsideredastherectionsoiepower Fitaitproprietyiethetérmpourspplid10 rarity,aneverythingcapableofputting@bodyin Motioniexpressedbythatname."Thusweascribe owertohorves,becausetheyaroabletodraw ' Monga.chariot;ortothecurrentofariver,oFto thewind,becamebytheirmeansmillsmaybepot inmotion, ‘There can beno.doubt, therefore, 160 ACTION OFGRAVITY. rityisapower,asit-forcesbodiesdownward: eyehegieeotogeiegover:Soe eanamaes F Galeeygovernthings1bocsfertbeaicanaestoBee Pete ber tetera aerate oe mee Aad reCreare ares eetSeatee ienecae Bereccreclameminog ete karate seems aet,t ea Soy,arecaae ofanSkinlertyheehh pleted Hegre Wher owingareno Goer ae eeBeem Leheeat poateoregon. tndenen ipa comes rees Feaessnenmen ceyee7ttngewe serpininebyereeeSeaameantica aretareae Lac,aymeee Tah Hiprafietroep aa si oma es ree eo Con eee RRR eeetecae sure’body,boingtransported ¢diferentplacesof ietieeaceaee Scr eeae ACTION OFGRAVITY. tet |tetuanowretumtotheaperturemadeinthe earth through itscentre; itisclear thatabodyat tboverycentremastentirelyloseitsgravity,2018‘couldnolongermoveinanydirectionwhatever,all thoseofgravitytendingcontinuallytowards.the {fagergravityattheconteotheoarwil0 atthecentreoftheearth,ifwillfo, Towhititdeacentingfotigcontreiagravitywill bergenimineedwescorglycone artSvcssprit,taprtportion eitepproeces Ercan,"Youthatbeablethen,ieither intensity northedirectionofgravityiacon foquencefmientareofeveryety,csnoteal fa"intensityisvariable;butkewiveTisdirection, whchonping fothesiode, bebe que Contrary."Havingtravelledinideatothocentreoftheearth,lotosreturntossurface,andascendtothenum: softhefortmousing,"Weehdere therenosensiblechangeinthegrav ea,Sheevorgastenoblothahe freightoftbydlslsoheeinproportionattre: Toves fromtheearth. Youhavebuttoimegine Sayer rmovngromorginil theaun,oroneofthefixedstats—it.would beidieuloustotaiekthatsent8bodymustfall becktotecathasiisthmostanothing {Siegelas"Henceytentmaybconlosed{hatabodyinremovingfromtheearthmusttneforge2amnion ofarity, hichwilbecomeSle andwl, eowhy dpa "Thore are reasons, however, which de thatabodyremovedtothedistanceofthemoon ‘willstillhavesomeweight,though3800timeslessfouytovweighS00poundsonthecathyooay to-weig aontheearthy0ay iseapeblo ofsupportingithere,btcam Moeailsanceofthemoosa core 168 navi or rmx moor. itwithoneofmfor.thenitwill weaonygeoundaptrerremoved wouldweighstilles.‘Wearecertain,there-fore,thagravityisapowerwhichforcesallbodies{erste centreofwearytathispoweracto withthegreatestforceathesurfaceofthearth, {bdisdiminishedinproportionaaitremovesfrom{encewhetherbypenetratingtowardsthcare orsisngabovetherurfaceoftheglobe.Ihave ‘ll muchtosayontissubject. 30thAnguat,1760. LETTERLI. . GravityftheMoon.1mavasaidthataderrestrialbodyplacedatthedimanceofthemoonwouldbereducedtoe3000artofitsweigh,orinolberword,wouldbeforced{Gwartheaneoftheearthwh«power3600 timesleasthanithasattheeurfaceoftheglobe, ‘Thispower,howerer,wouldbewuficientomakedescohocathyikwerenokngernpored istraeweareinespableofprovingthisbyanyex ermett,a0nomealexisOfraisingooryelvestouchaheight.‘Phereis,however,«bodyatthat ight—the moon: shemuetthereforebesubject torstectofrevit,andetwoseeshodoceact failtotheearth“TothisTanawer,thatifthemoonwereatreststerner lsttheepdmotionwhch Carriesheralongpreveatsherfromfang,"Therefreexperimenté which prove thesoiltyofthisan- eraaymotionintomedtpoayasImumeataly soymotioninpre i,falInlinedirectionoftstrghtverticaline,butifyouthrowthisstove, impressingonitamotionwhich forcesitoutofthatdirection,idoesnetfalimme | GRAvITY OF THE MOOx. 183 iatelydownward, butmovesinacurvelinebeforeireaches theearth; andthis willappear more Seaibiy inproportion tothevelocity’ impressed‘PX’cannon-bal discharged inahorizontal directiondeentcometotheethtilhasgotoacon. Aierbledistance;andworeitfredfomthetop ofahghmountain itmightperhaps dyseveIilesbeforeitreachedtheground.Iftherectionffcannon isfarther elevated, andthe quanandstrengthofthepowder increase, thoallwi bocariodmuch farther.“Thismightbeeariedeo farthattheballshouldnotlighttilithadreached theantipodes: nay,farther still,tilitshould not fallatal,butreturntotheplace’whereitwasshot (ff;andthusperformanewtourroundtheglobe. Ttwould thus bealittle moon, making itsrevolu- ‘ions round theearth, like thereal moon. ‘Youwilnowplease toreflect ontheheight of ‘the moon, and theprodigious velocity with whichshemoves,andyouwillnolongerbesurpnsedthet theshould’notfallotheearth,thoughforcedbytytowardsitscentre.‘Thereisanotherre- {fection whichwillplacethisinaclearer light.Wefaveonlyfoconnor thepthdesrind yastone ‘thrown,Oracannon-ball shotoff,inanobliquedi- rection.Itisalways acurve,sucha8represented ‘intheannexed figure. \ 1 qnavirr oFTHRMOOR. } ‘LetAbethesummit of2mountain trom:betastram nomtay|imthedirection AEFB,fallstothegroundatB;| EeraresSacer} shefarhdebence,| moreheee ee power ofgravity, itwould. notfall,hough Tetto feo avy Sou nr a ferhavingJecerioedtheeurveKEFB,care| BernscielBgcarenentfm|ifitweredestitute ofgravity,theballwouldnot\ describe acurve,butproceed forwardinthedirec- setsortmeseaaao Poti Fessawntvenethemom whichassuredly doesnotmoveinastraight line;sich eeereinatplatenPooppor Curvealmostacircle,suchasyouwoulddescribe ‘roundtheearth,witharadius equaltothemoon's Ttisveryreasonable todemand,whythemoon asarealeirmanyemore gayatpreaise, tenet ihrem eriysetteet,‘cannonball RredOf;thereisgoodgroundforrruaineisatySoeraneeSteeeeetateae ‘eters me peer pct Serratia, bested oa Paige lytmruboeshed iacmna faterath cena, ae Bypontcaebiahedmathomatien paeiplon, the OnIEnn oxarrrarion. 186 whichthemoonmastpursue;andthisisfound Felo‘agreewiththatinwhichthea ‘aire;aidthisisacompleiedencustaton ef= the truth ofthe anertion. etSeptenter, 1700. LETTER Lil. Discovery ofUniveral Grovitation byNeston. Gnarrry,then,orweigh,iapropertyofaller-selina kewlihemoon, sinvirtueofgravity moonpreseeeto: warebecrndryreebermotion Justaoitdrvctsdatofstonethrown,orofcane Bon-balltedof "To.Newtonweareindebtedforthisimportantdie covery.‘TsgreatEnglishphilosophertndgeome. cf,nageooaytobenag er tppletreeanapiefllposhisheed Ras tate ofebections. "Hereallycone curedthatgravywantheeaeofthepide filing,byovercoming theforcewhichattachedit {eisrash.”Anypersonwhatevermightbare matethesamerection; : perpornHemefarther.WonkthisreoreAwaysate!uponheiehdtheteebowsaareatafigher!Hecoldentrsnna doable Biathoightenequaltothatothe moon”Herehefoundhimselfatalostodeter.minewhethertheapplewouldfallornot”Incaveitsisae peared hm,however, iy probable,sinceitisimpossibletoconceiveotheeighthetroatwhichitwouldecoto itmustatlhavecertaindepres0 fring ttowards thecath;therefor,ithemoot ‘werestthesmepace,shemunbepressedtoward Sivanbyepiersarotwhichwood 186 ‘DISCOVERY OFUNIVERSAL fotloneetncojectateiatnonmight Rionhis)hecontoctared thatmotionmight =bethecaneoftie,jatasabombfrequently"Thiscomparison efthomoonofthemoonto‘thatofabomb,determined himattentively toex-aminethisquestion ;and,aidedbythemostsublimetry,hediscovered thatthemooninhermo-somone decovgrdthatmooninhereSearaeeepomPs Soakeihagueaaeadene ot Seeateadonaaoeteeaesats ieeeieSiewyupnyeeaeoan seatomsdle Siesta dondeerosoe Paronerenee fies iter omaptyof ‘theearth,thatnotonlyallbodiesnearit,but,tiSaeeeteeden menwcarretecremeoedence {iyanlrichminisee ta:roportionabedies .= a MrsteaeatwsneTerapoe ae eeee ees 18thocart,heconsoled,thatboutonadjacenttehpicepoweaspyandetbeane,Sreyetoneat Susgymitbreane‘reit witstanepottdtethetacooft tieSeaway we aesoutien memenrg oafive,whichmoveroundthemjustasthemoondoes earmarion amvron 187 round he earth could not bedoled tht the Toon of tin ofSapte Sontecbyelecartecms0atNe{hatoftheaeltenofSaturnbythts eration Beatie ca oftre: hehe sas ‘Stat Se oom mover rot he nth el Geir rowpectv sas move round pesoSar, atheplaneta homeeven moveroundthe Sun yence Nason few fe hao oa Foti connie, "athewnrowedwis LOSeeefacial Cleeerat euro,byapowerwhichmaybecalledsolargravity. Thsfovdr suena t'sroo’ Casas sunthnnrbeyond ueBanta SUSwetwhlcholenhtis,ue same great philosopher discovered themeansofde- ‘reli mabeoboefomheEaves otthpower tinytiastato 4c SeeaParteBatcretsieponeihet SntheattbrsStadpvemasts TERR mtn inEel tessshewaitoragedpore fepectnguootonofthnetony ent EBalerweaitraognect Sennwenoyasence , issstonloingtothinkhowmocoftheirpro-arealnonoweloaneressen” pigHadntvtec et rtheadataohaplyhateon tenowymightpreSalhaeSenmag SasiiofgunpcgWoone {Gotheavenly bots,and mulutndeofotherpoo-{GiediyBatogeterworthyofyourstenson, etfustallthereforebereaumodinafitureLatier=” aSeni, et SORTASE oeeer esSe 168 oyrus xvrest armmacron LETTER LIL Ctntin. OfthMiltrationofthe . feromlyBodies ‘Taz Newtonian System,youwilleasilybeliove modestftentoneawitgoodreno, povone had ‘hitherto hitapon adiscoverysoronyfortanateyand whichinedatoncesuchclearight overectanofepee haeon [reesebyseveralnamea,ofsichtinproperyou Koeilafrmateeiaeruaae Tthasbeendenominated thesystemofuniveralTitan;forNewtonmutated,tatnovovly {icartthehaventedieinrnaraeeowed’ with ‘stracting those‘Thichsurround teatwh¢powerimiattothet Sfweight oramiy; ac Gre theterm green, Thipowerishowerer,totalyie Eiri;forwesofothngacinguponbode,and Freeingthmttttearthaentox Tirethehesvenlybodies “Theloegcone,bywhich,ironandsteelareat. tractedthouGarbelngabetodiscernthecause,Pemesapimnomenm meniwine.Tour benowcertaintatthisproducedtysubstanceextremely mbtile, which pooetates toroogh theporesoftheloadetoeandoftheiron,iay.how.rerbeaffrmod,thatthelondstone‘attractfron,‘tianfooacidbyrovetheane ofspeaking.doesnotexcladethetruecause."It iay'ikewitebealirmod,then,thattheearthat alaltidhanaryhowewhich =tistancesandwe’maycont Seweightofgravityofbodiesatheedoctofthe ovTHE HEAVENLY BoDixs. 189 ‘attraction oftheearth,whichactsevenuponthetoon. Again,thesunandalltheplanets areendowed |witsimilarpowerofattrcton,whichextendsto |allbodies. Inconformity tothismannerofspeak-ing,wesaythatthesunattractstheplaneta,andS85SpierndSaturnaraterrenpctveae lites;henceNewton'seystemhasikewisebeende-‘nominated the system Ofattraction. "Aathere canfo'ondobtlbeswrysearthemoonmut ikowise| toitby«powersimilartograv- iy,iaayLewiso boaflemed tatthe008100 iructa adjoining bodies. Tewas natural tosuppose, that this attractionof themoonshouldextendasfarastheearth,thoughitmustbeundoubtedly veryfecbo,xswehaveseentatoftheearthaontegntbe:nowthe tamephilosopher hanplacedthisalsobeyondreach ofdoubt, bydemonstrating, that thefluxand teefheatorothengofwhichPal 0occasion ‘afterward, are causedttctionof ihenoonitcannvlongor bedocked, iberetore,thatJupiterandSaturn.arereciprocally attracted bytheir respective satellites; and that fhemun itself innubjoct 0the aitracton oftheplodhoughhstractivepowerbeexcodngy "Thisistheoriginofthosystemofuniversalst-traction,inwhiehiteonittsine,andwithgood‘eason,thatnotonlydoestheaunattractthoplanets,butieFeciprocally attractedbyeachofthem;nay,thatalltheplanetsexerttheirattractivepowerpotgachothr.) Thecart,thenisttracin, notnlybythoman,btalobyailtheterandthou earpowerboslmostimperceptible compared{0thatofthewun, me ms‘You wil easly comprehend, thatthe mation ofa %,which isattracted not only bythe sun, but ‘the other planeta, inhowever small adegree, en parremniejrtaneneafen Crumequely theuitncianoftheoorpacts ==ay:Inetcausesomesmallderangement ofthatmotion,papersin oec oem enay‘versal attraction tothehighest possible degroeof gre‘80thatnoonenowpresumestodispute onwieemahatamet rbSabres Scene etiaocetamneeane {antomthem.Itlaageneralule.asweshallecmts cues Seoe esate cme eeScien teeheeSaas When,therfore «cometpsnsomewhat more re gefiatlanebytactivepowersentsownwalSicietearame a Scena cnm ‘motion ofacomethasbeenderanged bytheattrac-Boos arepasta oeaabewefe ponphorairr omthattectonofcomets. meee oevueeanrencogcaioemsamormnenion pote Sisco sunroceers RESPECTING GRAVITATION. 101 LETTER LIV. . DifferentSentimentsofPilerophers repectingUnie eredGronn TaeAiactate® Irinestablished, then,byreasonswhichcannot be‘controverted, that ‘universal gravitation per- vadea allthe heavenly bodios, bywhich they aretracedtowardachoer;aaahiapowera ‘eaterinproportiontotheitproximity.hisacancontentabl BthasGonmado» sgnestion,whetherwoughtogiveitthename Grinsoratrctn.fhenameundoubtedlyia ‘Biter‘ofinference ufeetinheaun, ‘astronomer,accoslingly, attentive only Afioctofthispower,givenhimselflitetroubleto determine whethertheheavenlybodiesareimpelled towarde eachother,orwhether theymutually at- tmct one another; and theperson who examines thephenomens only isunconcerned whether thetarthattractsbodies,orwhethertheyareimpelled towards itbysome invisible cause, Butinatiemptingtodiveintothemysteriesof tur,itofimportancetoknowiftheheavenly jesactuponexc impalaion,or ‘racton; iceri ubenysemateynels thomtowardseuchother;oriftheyareendowed wiaacreorcellgai, bywhichtheyareRatuly attracted, Onthsexon phosoptere redivided. Some are ofopinion, that thi. phe fomienon isanalogousfoanitpulsion;othersmain. tain, with Newton andtheEnglish ingeneral, that ‘Redasiata iwattraction.{itmbe‘observed,thatthtermeeatan ae +thataccord inglyitanotfobesupposed thor fanintermedi36bodybetween thesunadtheearth. 108snrmasiesiwnonaeestesiemaganushteetetoe prattsme opinsBaoad howharptenegait oeieeeieee SESSotcation proiotapicatuner estate eteeaecifSeees ie Gr re tn innoinmeamathe casaarree Sautebaat Ereeeaman eha myo eye re iplgenetSreeirsa fei veence oh ee areca ty,mea feeacco theplanets inmaguitude,itsattractiveforcemust Somligrealertintisk"heyikewiseremarksgineenaetenes ieurtreeitteo reor aieerarioa amas thwmseeer cnn eeegheneeed Sareetasatia ealme,peeySeiretaonto eeteieereaSarayeteeuren toowouldbediminished, aswellas.thegravityofsei ses pisayne tanontheir sis,anytwobodies whatever atrest, ISeinmaneon oleate wahherandiad (quence;buttheyinna,thatinthcasethoait GentryanOlnee ‘ifect;forifthewhole:massofthoearth,byite reason orrun mariner som. 18 trative free rode inevery dy ony dahecwhichweoreivemtheweltctby. EP STRSeiinestleten bsah peter fa may ines mtiareoliybecdnital atewe wyattnayeluese4gk itaryelated outa ASSESRectorate ee Bieoy patopt Tore Bepanolfalaerresta erable onthisside;andtheyproduce insupportof Egyotrpeine’ Sue's Debye PeesPaneataTepee te Siaraigetalsendnoma Rpeam carne career telitesrn Fis itng hie cantrgeae ascrsbeigecngnsas Sie toon nee ‘7thSeptember, 1780. , LETTER LY. ery ihteHey Bbeemay Fim ouaewellsomiedwihtepopertyoftho Joanne:tatoftratingrn.Wor'haveseen ‘small bits ofiron and steel, such asneedles, when Sinafens te aeMu ee cerntseros asyoohe fingthatimpelthemtowards theIondaton, we “Ye tyttt.ESS eaeSty i lea cer 1% arrucron or ra saythattheloadstone attracts them, andthisphe-Pedeapen prienheentd however,thatthereisaverysubtile,thoughinvisi- Areeeeesduceianecna tetaoeofexyocuionsrerogusted tyspresremen, 8ee rePiecaeannySeyaeans "Thoughthis abepeculiartotheloed-“Taliepenmeonagran taaeeeilyadaptedtoconveysa italic enaBeetalfoaontingoserl a8endowedwit oyeauanen't 0eoume’peropil ienethysreverygrod, 2ue aa Pereyry‘However great,forexample, astonemaybe,it erasErasesaatotoerBaie Fans Peeters oadBer Seetad eae i Stansofeepeteessweaea Neen a eikacieedy ean Ta action eae eaeSEaeaeerahat’potucedSiratia,eerayeromadaceoasis Rehneeitreracethereanonseat Seoatromecgery ea Bi rey amis Ray ac ena rane eon eae Pe ‘cisely thegravity with which weseethatthey are SSRheeheheraritywhich Rs entryfonofarcotewemaneOt{weightofbodioewouldbeproportionably coe omerAeratheakpret ‘bodies intheuniverse, abthesun,theplanets, and mraventy pootes. 198 |themoon,areendowedwithasimilarattractive Power; butgreaterorleeeinproportion asthey themselvesare40. ‘Asthesunismanythousandsoftimesgreaterthan theearth,hisattractivepowerexceedsthatofthe earth80imanyhoundtines"Themassofthe‘ooniscalculatedtobefortytimeslessthanthat ofthecariitwilfollowthatheretrctivefoes s0manytimeslesa:ame ioeallthehourenlybodies. rl ihSeptember, 1700. LETTER LVI. ‘Theseme Subject continued. Ixvirtueofthesystemofattraction,oruniversal ageviation,cach‘oftheheavenly bodiesattracts alTost,andisreciprocaly attractedbythem. ‘inorder toform ajudgment ofthe force with ‘which these bodies attract theothers, wehave onl SDconsiertwobodieswhosesttractionismutval. ‘Aherewomustatendtothreethings;fet,to bodyattracting;wecondly,tothebodyattracted; fd,finally, totirdistance’ foronthesethree ‘ircamatancea thealtractive power depends. “ig. 33. et A,Fig. 38,botheattracting body, and Bthebodyaitracted;bothofthemspherical,theheavenlyBoalonboingnaryofthis gure, "Takofortherdi ‘ancefstoftheirCentresAandBthatsthestraight 98 srrasoranorrex lineAB.Now,withrespect tothemassofthe‘attracting bodyA,itmustberemarked, thatthe festerthereataolbfporeSoageSayaCosacondyAaaeee asgreatosB,thislastwouldfeelatattractiontwiceAeneas ects weeetwrrn . Tatas eSoestoe"amannet te Feodiceereioieg ‘If,then,theearthcontained moreorlessmatterthanitactually does,itwouldattract alladjacentSEGREtaldoomtrondectce osviteordinmits” Sueet Mea aeneasatesa taryhappentochange tythettractedbody etahagaa a Fee ciateAteamtnOy SansiMtoateiseafeaaries,t,othepowerwitwhcht Epaiowntes‘Thanfineblywarwien serentAatttadnecesEan Beis,Witsnepeerwitise Inordermoreclearlytoelucidatethisremark,we Ihaveonlytosubstitute theearthintheplaceofthe Boyihstrictedinnothingisebutthoweight A rh seeshsteA es SpitpeatnaeAweResea Merits aystags dre eas‘thesame,theattraction whichBfeelsprecisely fol-a etdramanchmettg elytetorme ;thus,theysaythebodyBisattractedby bodyAwithaforce altoitsmass; - Cocaheerienary eementingofchCaemateaie arte _— meaventy nootes, 19 creased.Thos,withrespecttotheattractingbodyAhoaTheroverichexereeispropoRionaltoitsnae,60loga3 thatofBandtheGstanceA'Bcontinuethesue, Tivoatfartherobserve,hatwhenwespeckofthe ityofthe attracting bodyAyoroftheattracted Bywemean hequanstyofmaterwhicheach tidnothermagtodermerey Youwil ecole, hatbodies diferconsidera inthisre-|pectandthattheearesomeswhichinterysmal Chapacontain prot Salo mater gore epee thersuchacontawryHie intgreatspace,"When,therefore,weherespeak ottien, wearealways tobeundeetood aeterfingtohequantity ofmatterwhichtheyeoataan? Baiewet veekabythsees "Al that ow remain isto examin the third ci- gxpwance, manely thetivhoce ABofheoo dies, eopposing themfocontin aways thesae. Wrinute beobserved, tat aathe distance A'B ine treanen, theattraction diminiahes andthst axthey Sppronch nearer, inereuses: buinconformity 1 Tiler which ifWnotoo eytoexpress,Whenthe Gintancebecomesticesagreattheforcewithwhich fhebodyBinaratedtowardsthebody’Awilbe {orice two, orfour fimes less andfortp hedee{ncetheattractionbecomesthretimestree,that fs'nite tines fos ifthe distance becotee’ er tinespee, theponerofctionbecomesfor fimes four, that iswxteen times lesa, and n0on.Finally,foradistanceahundredtimergreater,the wroy ofaraction wil beshundred tives hu.redortenthousandtimesless.Fromthsitfo}therinpecefche. Andrciprocly, when impercepuble. And,reciprocal,whenfhe'otace AHveromathotacomayto"veryconsiderable, thoughthebodiesmaybe Dogreat magnitude, Spt To 198 ATTRACTION OFTHE LETTER LVI. ThesameSubjectcontinued. 1mavenowdemonstrated thatwhen2,bodyBia ssactsdbytboyAhepowerofauaclonfoemanoftitecngody iothatoftuearaciedbodyBybu&padsfoveush'sogresontedntoftheseSone,{halWanolbecome’vice,ic,fourorvsEinesgrote,theporeofsgscueePodbosons four,nine,sixteen,ortwenty-fivetimesless. Trortosoeraiatho‘aleofnegettting wwe" muet mult into foelf he nua wiseTinebowmalttinetheGutentserenttoldpredielvilauoy howmuymeena forverofsitanionhooBecomesToputthsrue {nitsclearestlight,tmustbeobserved,thatwhen etmiliytaterinoueteprodurere TipBumitseuledispor‘TakYofadthane defare,emus!mulipytenanbersbythea ventbelow Wangan 8 sent3]33/3)313/413)8 vee a | men ten Isisclea,romthalstexamplethatthe otmieaEayorihkacoe oroxyauntwhee’, ‘netSSuleptytialmmaberbyefattheDaaowing EAVANLY. noDuzs. 190 258 i 258 2006 1300 cy 604 1EWTSteure ofsnakesoatovarmayboca‘nurobers whatevermi culatedinlikemanner. " ‘Aathedistanceofbodies,then,mustbemultiplied iteelf,itisevidentthatthepowerofattraction haciakesasuchostheeqireoftedistance Iacreans;or,thatiheoqareofthedistancebe: ‘comesasmanytimesgreaterasthepowerofattrac- Son's diminished. ”intrestingsubjectsofthisnature,mathematicana ceuployexpressionswhosesignification itisproper yousouldKnow,becaweetheysometimesoccurInerenetn proportiontofheauarofthedance, inesquareYeroucalpoprtinally tothesquareofthe Extanco;butasthedirectcontrarytakesplace,and. ‘atheattractivepowerdiminishes asthesquareof‘hedistanceincreases,weemploythetermrecipro-fiverisecbrocalyproporcooatotsunreofi are0 Rfe'distance.Itis4geometrical modeofexpres- sion,themoaning ofwhichyouperfeclly compre-Hood;andireertowhatIRaveJustbeentempt. t6explain.‘ordertojudgearightofthepowerwhichonees‘thatthispoweris,firstofall,proportional tothemassoftheattractingbodythentothatof ‘hobodyaracod;andSaaly,reciprocallytothe ‘oquareoftheirdistance. Hnceitisovident,chat 200 orionoFTHEthoughtheearth,andtheotherplanetsarelikewise pert attg cog rebeimpeoepible onacountofthirproigiousdix ‘rtiposing,therefore,themamofxedtaro torthatofthe‘son,at arilwoulboatractedtowardstwitaforcews4stowardethenun;butaxthedistanceoftheEredtariSooniegreatertantatofie san, ‘umberbeng160,000,000 ‘hatis,hundred andsixtythousand milions: the owerwithwichactapoourglobeiba tndsixtythousandmiltoeoftimeslasthan thatofthesun;ani,consequently,toofeebleto ‘produceanyperceptible effectPorthisreason,the EitractivePoweroftheSedstarsdoesnotatal Aifect theeartt's motion, nor thatoftheplanotsand fheoonatstaoftheamwichchy ‘ogulatestheirmotions,becausehismann Biaonan ftiehemansofachlant, rrever,twoplanets to theirdistance beComes feesthanthtofthe.sun, their attractive power increases, and may become fuficientiy perceptible. to.derange:their-motion, Sach derangement has,infact,beenobserved;and conmtittes ‘anirresistible proofofthesystemof veraravatin, Accoringy, whet«comet {proachesveryneartoaplanet,2 iBtmay becoalderably fectedbyi 13th Reptember, 1760. LETTER LVI. MotionoftheHeavenlyBois.Methodofdetermining CyTaefener rant ‘Faomwhathasbeensaid respectingthepowerswilzhalthehoevealybodicetuallyateeconck aarone soos. 21 alee, proportionally 10ther mans and distance|SortlEleZompraedowthtmets |raeeemiahes somyrendAerinos Te gc tines aceeney Soren rere whichia ‘mexactknowledge ofthemotionsoftheheavenlySameera ofshamotionsofteevenly eetotlanwnethraaart: etSrriehenccibeu ntbaalarapet ee ee eePe‘earth,oranytherpoint‘whateveroftheuniverse.vam riya " Bee ein Sa ded wince ane scat powernace cn seerhepansvracherofwatioantes aades telancheofmathematics and iechanice10thehighestpossibledegreeofperfor eeeTaal Semeatestoaetwlan pyep,"mayyon ideahaamengenyeNotalyYon Fane a Eat shiaeireracento elySusi teens ancl se ots fn pres Tig rooney sonegeen‘Thegreatest difficulty arisesfromthenumberof Feee ‘ofthesewereattracted towards onlyonesinglepoint,therewoulbeveryitidielintheway’and eeeee Re ate |Piru abouts Sitpee beatresearch,todatermine itemotion.”‘Thesamething 202 orton oF rmx mEAvENLY poomes. would sppty totheother planets, Saturn, Jupiter, Mare, Venus, andMercury, ifthey were attracted nlybythosun.ButtheGarthboingattracted,not alybyhim,btbyalltheotherhegrenyboo thequestionbecomesinfinitelymow’complexandAiticult,fromthegreatdiversityofpowerstowhich‘wemustpayattention."Youmayneglect,how.ever,thepowerswithwhichitisaltractedtowardstheodstarteeamsehowever,ormoustet mastes_may be,theyare80prodigiously” disthatthepowerwhictheyexernepontheeaimagbeconideredaunothng. ‘Tusmotionoftheearththeetore,andofthe otherplanets,willalwaysbeasperfecilythesame seitthedarotent"Bxoopng.hen, ‘thepowerofthesun,wehaveonlytoconsiderthepowerwithwhichtheplanetsmutuallyattracteach‘ther. "Now, these powers are extremely omall,‘compared tothosebywhicheachplanetisattractedtowardsthesun,becausethemassofthesunis|auchgreaterthathatofeachplanet. | ‘As, however, these powers increase accordingax thedistancesdiminish,#0thatapowerfourtimes{eatercorresponds toadistancetwiceless;anda Powerninetimeslesscorresponds toadistance Three times greater, and soon,according tothe‘oquaresofthenumbers,asIexplained tho.subjectithprecedingLetter,itmightbepousbefortwo planetto approachsonearthat‘theirattractive powershallbecome‘equaltothatofthesun,may, GreatlyexceediFortunately, thisnevertakesplaceinoursystem,gatthelaualvayyremun'at rchadntaneefromeachother,thattheirattractive powerisover Incomparably smaller thanthatofteaun.For this reason, without extending our views beyond Trerypiset asatracedonybytheperof or=‘only.bythepower tum,afdbythatitiseagytodeterminetemotion. rreren or rum onivamse, 208 This,however, cantake onlywhenweareTepoesdayeratawinsrornearthoruth, fort wewith tohave more exit information, we ntaloes lerporeswitch te Planetaactuponeschother™powers whichretheliefreguantes clearlyobuetvedEtronemes;andfotbestipeoteTeed Enowledgeoftheseindirectodallthesaga Totrastronomers andgeometricians. ¥ ih Soptonber, 170" LETTER Lx. System oftheUniverse. InorderthemoreclearlytoelucidatewhatIhave toon ‘sivancing rerpectuig the motonoftshee relySlee owenwhchpeice ihetopresenttoyou(eeeFig.3,Fron) theaywtemofthemivereeyora‘deacription &te Senycalybodienwhichcompose it "We mun, st ofll,observe, thatthe fixed stare saebodies sntrey similar tothesun, andfuninoae fects ththeyarowaverygreatdace 8 Kfcahatminry,sdloerydanomeach ‘ther;andthateveryoneoftheminperhapsof qualagitwitusoararea ‘Simed,thatthoxedstarnearesttousiateast 400,000 times more distant than the sun.” Each ofiNeRandwaeneedeinetocommtniathtsoihea acer nueoffee baieaJartoourearth,and,undiyinhabited like- Winey placed near them,butwhichweeannotsee, omaccountofheirprodigiousStancecbetrrefias wsfistconiatofomieeecatogytotheron,whoservestowarintnd10lum ‘ietheearthandtheotherplaneta."Weknow, 04 vereoraearena. particularly sixofthosebodies;theyare‘uotin BiteofrvsbatcachofhommovesTowSheey {inthedirectionofacuvveline,somewhatdifferentffom«circle,andwhichiscallodtheanot'sorb ‘Thesunhimoeltisnearlyinastatoofrest,aswell +asallthefixedstars;themotionwhichtheyappeartohavebeingentirelyowingtothatoftheearth.haveacoordingty represented, ontheannexedsheet(ig.37,Prone), whaicaledtheSer System,whichcontainsalltheopaquebodiosthat moveroundthesun,andderivefromhimallthedenefitewhichheimpariatous.‘Thissign@repre-cieenropreceting thouescibedbytheplan ire00 “thatnearesttotheunisMorr,marked ‘sun rh thoi'satoitecleyousosintbeooh‘epresents thebodyofMercury,whoperformshis‘evolution roundthesuninabout88days.NextcomesVemur,markedby2,whocompletes‘arevlution roundthesuninsevenmonthsnearly.‘Thethirdcircleistheorbitoftheorth,markedbythesign©,andwhichcompletes arevolution.oundthesunfnayear.Wehavewoothermean- 7{ng,intrath,tothewordyear,butthetimeemployedbyeearthinperforming‘revolationroundthe ‘smn;andthedurationofthecommonyearnearly hestothissolaryear. otwiiletheearthfemovingroundthesun, horeisanotherbodymovingroundtheearth,endKeepingthedirectionofitsorbit;thisistheAfoon,howeowntrl,ororbitmarkedbyDy”twofirstplanets,MercuryandVenus,have novisiblebodieswhich’attendthem;neitherhas ‘Mars2,whichisthefourth,andperformshisrevo~ utioninabouttwoyears, *"ThenextcircleistheorbitofJupiter,markedby2,whoperformshisrevolntonineleYoure (GTOTEM OF THE UNIVERSE. 208 inthePlate,withtheirorbits,andmarkedbythe figures1,2,3,4.shunpe'hoeaployeabsttyyoursinpor foveingonereralioaroundtheaThspeach [Ratteedinhscourebysvensatelite,marked bythefigures12,345.02, Ththen,‘the“yas cota ofieBaeteMerearyvenue2Shears2,Kare2 opto2,Stir.byandeightnensecondarypan” ‘etsoreatdlites,namely,theMoon,thefourtend: itaofJupiterthosevehofSaturandteiof ‘Spalefatomcontin,besides,sever!comet,theoom coved connumberofwhichtsunknown, "Thegureon’theFate ropesensoneofthem,whoseStaides fromtntoftheplanetabecdveNsdrawnot E20exene lng sth acometsometimesproschverySertothoun,andsometimesTemovestoeuclanimmensedistanceasentirelytoSEtppeny.OFcomesthaneoToma,atto Eeishes is rvoletions tnHs Orie intboetsixtyyousthsWethe‘onothatwanViablefast yeuks?°s tothe ether comet i'm cera that They benloy noreral geomion Inperoruing oserevolution intheirorbits;andas,inpastages,noSructbeerrtions werenadeofWen,beeefgtalyithedtwihrepttothereto,OFane then,consisttbeclrystemsachmetprobaly, veryrelstartasoneTenerioit TH Bpeomder TT eeeetnwfeeet Preah itn) gl podErewimissa meee be Srpeaes AOS mE «meer fon.18.“— oo sverexorTHEUNIvEEs®. . LETTER LX. ThesameSubjectcontinued. Ixaddition towhatThavosaidrespectingthe HaeOthe explanationoftheres,Andsfret ~oles.ANd, sin iontheplanetsovehaveoowoolexat "in whi ‘move have no re ‘Snoeintheheavens,aathewholeimmensityof inwhichtheymoveisvacuum,orratherfiled ‘withthatsubtlematterwhichwecalltheether,‘Maguteoaoftepalaolinthe e‘the ‘renotallin same plane,axthefigurepresentsthembutifthe Orbitwhiehiecresrienroundtheaun. Treborofthefiveotherplanelatobepartlyelo- ‘aie,andpaydaprenpod,withretrencafot OFthat the orbit ofeach planet bears upon itan fbtique direction, making anintersection with the Paper,underncertain angle,whichitisimpossible ToTepresent ina gure drawnupon aplane.oe,oisofthepanelsneacircle, - ‘appears1indicate,butrathersome:siacme nae Secsever, ‘veryconsiderably fromthecircularform,"ThoorbitofVenusiealmostaperfectcircle but thoseoftheotherplanetsaremoreorleasex: tendedlengthwise,sothatthesoplanetsaresome timesnearertothesun,sometimesfartherof "The oilsofcometsareparticulary distinguish able, being‘greatlyextendedinlengtha8represented inthefguro.-Aetothemoon,andthesatellites ofJupiter andSaturn, theiont,00,arenearly‘Neither mustweconceivetheaasmovinginons sverex oFTHE UNIVERSE. 207 ‘ndthesamedirection,astheyappearontheplano {fthe paper;fortheydonofremin inthesameace,InPcothemescariouthaa ngwiththeprimaryplanettowhichtheybelong. ietius wemstunderstand thelinesrepresentedfnthefigure.Imagination mustsupplywhatitisImpossible,onaplanesurface,accuratelytoexhibit ‘ouarenow enabled tocomprehend with case ‘bat thelateMr.deFontenelle meant todisplay, in hhisbook onthe ‘plurality ofworlds. The earth,‘thtsinhaitani, issometimes denominated orld;andeveryplanet,nay,everyoneofthesat: Gilessaanogalabothesaeapelin lyprobablethateachofthesebodiesis Hint sstala the arth ‘Therearetwenty-nine worlds,then,inthesolar system alone.”Andeveryfixedstarbeingsun, roundwhichacertain number ofplanets perform theirrevolutions, andofwhichsomehave,undoubt. ily, their satelites, we have analmost infiniteumberofworld,similartoourearth,considering‘that the number ofstars perceptible tothe unas: fisted eye excoeds some thousands, and that the felegeope discovers tousanincomparably greater number. Ifitismeant tocomprehend under thename of world thesun, with theplanets and their satellites, andwhich derive heat andlight from him, weshallhhaveasmanyworldsastherearofixedstars.ButAfbythetermworldweunderstandtheearth,with alltheheavenlybodies,orallthebeingswhichwerecreatedatonce,itisclearthattherecanbebutone ordtowhichworefereverythingthiists, isin this sense theterm world isemployed inphilos- ‘ophy, particularly inmetaphysics; itis inthis sensewweaaythatthereisbuonewordtheassemblage Ofallcreatedbeings,past,aswellas.presentanfature, whose existence issubject togeneral laws. ‘When, therefore, philosophers dispate, whether ot eesovrsores oewanttetnogotaygedonhesurhetotyzat Sermeenetaioretrndconte whichcouldhaveexisted.ahpi d Thence hncnn!encom ningne,ah whenpret == Saatamarante dre GiftedoortheeuriazeOFourrideaadwich Sopa enepapaiasrnatecoors acdntonmanoety madebetweentheplansof2worldwhichshouldaiiateesnase ceecongaicth Samraeeote‘wouldbeinvolvedinverylittlediffcalty;but intheother,wherebeingsiteligent indfres‘constitute theprincipal partoftheworld,thedetermi-Seheriniee tere beoatbtnityrode fotothepetctionoftheworktinamanner Eiecacearerimac wanton Ecotnteereetten abetoneto renters op tex parare, 200 LETTER LXL Small itvesintheMotions ofthePlanets,rpcfoDis aleliton, namely, themo0uthefoursatelite Of‘Tupiter,thesevenofSaturn,andthesizoftheGeor-‘gum Sidus. FrSenatortateeeeenpie ‘aareprincipally attractedtowardsthesun,orthal yest tutteiernie he Pe tnetheirreciprocal attractionveryconsiderable.Feenstra tycrea tion ‘besufficiently regular,andeasilydeterSeal rely on odcy ceBepeercement achepson Srrendrieh generic cients Sreyena Patoptopi hyatigtetoretoddplesabove:fora,regreacquainted ‘withthe Bonaorsiddoeneneget oe Expjected. Thusthemotionoftheearthissome. SareeTieteeinfereaoe SeefyBecton Coma thatofpr,which,onacount‘oftheprodigious 10 —matovarrmsotrn ‘massofthis t,becomes considerable,mestalsraetbecamsconcentaneSe eee es NeerasYTro ‘though hismassbethegreatest nexttothatofJe Ftheraanbeverysmall,ro dareneelMermuchabe fiisee's” “Featwhpearl SereaeeemetnceoteteahesatEeveepossorctttmuySave eryimc egetihsmass Cr es a,re Foote Reem’veegets Byeae,eahaehenryttt siSatsangeae arseSates seteHarem teeeatecepowerhagoPeper captepeeaad Pereetn,asnasbaneappocodtoey aoeercingtndeoctets snusEnterpiceows ‘imtheotherplanets, regardbeinghadtotheirmass,eeeeeaccaolts otheraecondatanol,theprincipleoftheirmotion:tanksiattheatbetionhefeesromhenceprea ttee faiteataya mas6 Saree hensofnert Sreeeethateoeota ‘moonfollowsthatoftheearth,andthatsheremains,en ayeiwiehteatestoooneleoorbemlacedmackfertrom ahiiooneenaoe! ‘thantowardsthesun,shewouldhavebecomeapri~ wonioxs oF THE ramets. 11 andperformedherownrevolutions foushe‘sinyuthelsSo0tinonetorfoos thanebefewtheran,henceitevidentthathe tmurtexercise»muckfecborinfluenceuponher tiantheearthdors.‘Themoonbeingprinlpal tractbytwobodies,theaonandtheearthyH vilctthatthedeterminationofhermotionmmst So'touchmoredifteattthanthatoftheprimary* neawhichaeetefotheattractionofig Eumonlyrexcepting thealightderangoments whl Invebetamenos,” ‘Tiemotgnl tenoonhat cordingly in ‘cmberramod plovo,flere:taseverveheyRonaletaera forayturegiventimetheexictplaceofthe moapence comprehendtatinorderto om"comprehend thaictanoclpeewhetherofthemoonoroftheban,emufleacuaytomcahemoon Jlnce.Nowincalculatingeclipsesformeriyythereifeqaly pteofaaorte Speeoct iceanhourearieror eb‘the calcdaton’ Whatever poistheancteot tetronomers tok fodetermine themoony motion‘BoyweretwaysverywieofthetrotItwas TailthegreNewtdiscoveredtheretlpowers ‘hichatufothemoontatwebegunoapproach Taregdnearerfotayafer vingwanedyar SalamstteSono jocksandMe.MayerofGottingen,pursuing iheacchUkadopenedanaridateeotprecisionbeyondwichtis r Goisget Notmuchmoro,thenthantenyears Seer‘etnorsrnovel)havespateropesofBiSoa saeStrateoMayehnwhepreo 213 DESCRIPTION OFTHEhaveelapsedsincewocoalbustofanythingIke pabhenpwhaeeigta tir weto ‘thattime,weareabletocalculate eclipses 80ex-‘actlyasnottomakethemistake ofasingleminute ;whereasbefore,therewasfrequently, thedifference ofeightminutesandmere.Toanalysis,then,we seedfrtmponandecry.ore cnpeatole advangeaottobeaot Sa aTotalie FadSeptember,1760. terres La Description oftheFlusandRefluxoftheSea.‘Tenattractivepoweroftheheavenlybodiesex.a reeteerentbedseee ae, ea earachegompone,hamahe Se ie one iors cach foal heessi,otoyearcachaefromThteebeBevantomasfeest‘towards alltheotherheavenly bodies; andthateeccaattsTheaestonyayasioneasedlowandsthe”oany betesAreepraeaeedoan eee etdtiiepaneaahemoanbernofhetat Breeideemaeeaten as Sreeneue raimeps 60timesfarther fromthemoon.Though, '‘the ‘whatsareigeareoohyenioeoneepeA pctntara eae \ YUEANDREFLUXoFTHEEA,218 tansofthemoonwereequal10thatoftheatt {Geratraction fowards the moon would be60times {heleneortepaviyofthebody."Dutthenase or: ma ofthe moniabout70mesTeohanthaofthe ath;hencetheafractiepoweroftheToonbe- Somes sil 7times 3600, thats, 259,00 times las ‘Bebe ganiy oftheod‘unoughtanbemanyhoundsof sineeterhanheathheeboa3,00tines toreGotanfrom‘usthantecontreoftheoerhy {Endfortisreasontheattractionofthesunupon& one isextremely small compared 10s gravy. Hencoyouseethatthegravityofteretralbodies, ‘Whichinothing elsebuttheforcewithwhichthey:$yactedtarthcathycannabeperaiy"ateiobyiheavalonoftheheavenly "Though this attrction, however,beveryincon- sea,theeentsfom18emaralpe-omenon,wichlongpustled er;1mean OcaorthefttheroxofhoauTk covars0fequettly, evenincommonconver SSTmancemiterofecmfotnd Forthireason,proposetoexplainmoremi ttlthlealrphenrenon, alouldte Saene whichfod Tbegin, then, with thedescription ofthe wellInovaphnonenoneftefestniteofhe HEAnyoveenrant tabyYrpein, Pareol tie eartac ofourglobe Wscovered With aManeofwater,calledthoem,orhoorem.”This Enmeaoe Seid ems bsvory ifeent tome rer endlakes,which,accordingtochediferentseabonaof theyear, contain sometimes Tess water, sometimes ‘Bort,bean inthetentegua ofwaterSirtinescontinuesearythese,{ishowerer Slimerved tat thewater ofthe sea rises’ tnd Tals a pesckirrion oF Tum siternately withwonderful regularity twice everyiesoteRousitagrectentheightwlproeutybegintowable, iinpretestheightwlpresentlybopa :tafhiedecreaseSoctinuesforaithotre,attheoodofwhichitedepthwillbeatthelowest.Itthenbogiasagaintorie,andtheincreaseikewiselastesizhone,whenIiagainotiGroasestdepth.it {immediatelybeginsagaintofallforsixhours,and thearisesamany;60thatinthespaceofabout vehalteranelyategestsandlettGophe arnves aKegroatentandleastdepth. t'sthsalternaie increaseanddiminutiono¢the towing andebbing:tndmareparncaleay,the fxdenotethetineduringwhichitincrease.or Maneandthertthatieofideerateorf rheflaxandrefluxtogetherlikewiseHada aeeefectofourpresent disquisiion.pitishrtalberemand,hatthedorenco weenrs jingKeepapacewiththevaria- Honsofthemon.Atfallangnewmoonthewater Tises higher than stthequarters; and about the timeofthevernalandautumnalequinoxes,inthe monthsofMarchandSeptember, thsalternatemo- lonoftheseaismostconsiderable. Agreat.dit-{renceislikewiseobserved,accordingtothesituationofthecoaat.‘Theuxinsomeplacesisnevermorethanafewfoet,whileinotheretheriseis fortyfotandspwani.”Suchrethehanintheorssot StalinRanceanofrainBag Itisfurthertoberemarked,thatthisphenomenon {aperveptible chieflyintheovean,wherethereiva‘abtextentofwaler;andthatin’seasboundedand ‘payPye gh08taaneaayOe |YuUEaXDREFLUXOFTHEsea,818 ConfinedrachastheBaticanitheMedierencan, ivismuchleesconsiderable. ‘Theinfervalfromthe |uxtthesucceedingrefloxisnotexactlysixhours, |tataboutlevenminutomore;sothatthesame changesdonottakeplace ratthesame fourth ‘fallotsotthree-quarters aftnboutIne90atarevoltonofthirtydayIequine to’rngthomroundtothesameou;now,tisis precisely thoperiod ofonerevolution ofthomoon,Brthe Interval between one new moon and that ‘which immediately follows. ‘60h September, 1760. LETTER LxItt Diferent Opinions of 8respecting thePlusvalngsofteSe ‘Waxthewaterofthesearisesatanyplace,we axenottoimagine that itswells from anyinternal fause,asmilk:doeswhenputinavesseluponthe fre. "The elevation oftheea isproduced byarealIncreagofwaterflowing‘atheromsomeother lace.* Itisa realcurret, whichisveryEe‘atsea,conveying thewaterstowards theplace ‘whore the fu is Tn ordertohaveclearcomprehension ofthis, ‘youmust considerthatinthevastextentoftheocean therearealwayepiaces wherethewaterinlow,while itihighatothers;andthatitisconveyedfromtbe formertothelatte.Whenthewaterrisesatany lace,hereiaways acurrent, conveyingitfom Dtherplaces,whereitsofcourseatthattimelow. Ieisan error, therefore, toimagine, with some tie‘hore,thatduringthefuxoftheseathetotalmane2reatpertteotomrhb asiegeSOAplsoaSr neneemaneaMeert,etion oh” geeateats Soeaenraeereaces eke nae i ae aa Fertickioetientotems Eeerinyposers hb Thon whereitisow. ‘Sucharethephenomena ofthefluxandrefluxofgeeeaterteenaete deavouredtodiscover, butinvain.Kepler,inother spatfattateaeReed Seaeran SaaS Se Sie Eyam ae icaricarigharenrecaravaactsfuweatswerefontIemooseoedingofthe iorsipaeetcocea Euanhae Descartes, that French philosopher,endeav- ebiaiteree reais entEmcueme nereraneae feetwophenomens, Forifhighwater,orthe topoftheflux,happento-dayatnoon,itwillbelowaoEee y cenadigmeeuamaetee8 Friguieatiseairigoases ieiaeessear aea fromonedaytoanother thesametidesarelaterbycaeichtnnytenesne ‘moon'smotion,whichrisesalwaysthree-quarters of wren omseerigtaype,es ei moresare eae neat.ewmosoyhighwaterhtobeat‘oftheSaaspeaifoar Perea ae Erb is tints abieeat atte atataiarmatete sib ct Rim measSee Cem tenerst+tafterthenewandfullmoon,thatis,attheseirecteaeiiatea imc elevation ofthewater, during thefux,issmaller. Se See ee Se Shports daaBanas eeeeee ‘tndreffuxoftheseawastobesoughtforintheets‘Descartesaccoringlybaliovedthetthemgon,in maracaswa eee aRenae creasae pressedattheplacesoverwhichthemoonwas,and Kemaaeieee meme jintheensuingtide;which,however,doesnot.hapfayBe eee eleswhmadereoreerasieee, orn esaciedkavaravatal Gree aaa‘Thisattempt ofDescartes toexplainthefluxandTee sam umes eg Sommers sheeSasiemalzeeert tocmploythesptionionofta Sara ae Peart Ea Fla LETTER LXIV. ~ Etnaeefe BhiodSaharBing Descanres’smethodofexplainingthefluxand refioftheses,bythepressureoffhemoonuponeeeSonatetookforthecateofitheattractionwhichthemoonexercises upontheearth,andcon- .Sysin tebe ‘therphenometaatIhaveshown,collactitera rereme de haSera onaaici inthedirectratiooftheirmass,andintheinverse Prehended thatitsactionmustextendtothesea;Rianne us Srarheceua larsay Toate anabeat eeeet Berpyaecelleofocife fhagitationKnown‘usbythenameofdusand oFTHEsa. 219 dattneredteen,3 Fig.3,representtheearthos: bie nse G2 Hathtetntent PeaTeer nacrei Eerosans teinmorepowertlyatactadcanesans oe ms Reyespacedate r2SecretarPe Sen eed a eeSyatSahn utycrhg Sy hayimasos Tehtfeaoeik favedotEandFerejinoettemachattractedby Seriearora ena SreyLtTosemaasSeSacaneehaeareohce oftheeartharenotalequalattractodtowardsthe ‘moon."Thisinequalityofattractiondependsonthe‘inequality oftheirdistance fromthecentreofthespoonL;20thatabodyis#omuchthemorepower. fullyattracted bythemoonasitsdistance isless; Sr ce eae rte bodiesdiferoniysfied weororechetbyraatSactooraaceeeyed towards themoon,theywouldequallyobeythie a0 ‘FLUXANDREFLUXporeseplnsdemproat reat>yt re giant Se tet at foceyfom ! gine Gagne osDegree edaireseringaeghee ioom reSoe pee neat pee ance mate pee SeeieeelSar Care Sar beeen meni erat marae hancewien Taeamesones Rec atarianata potag peel mgtErettiached ioeuchtherbyundewichthetpow?pair ion a Bs tnowsat peal Pabeceamp an eet ninosel ase thepowers whichactonthedifferent partsofthe ‘s¢aarenotequaltooneanother, anagitation, or erangomontustbetheconeagonce ‘Wehavejustseenthatthedifferentpartsofthe ‘seearoattracted unequally bythemoon,accordingSS ara eeeres ose te eee see as Tse i ae rie meal sie apaarSaterbeceased Term,makesthooonuatergothesamechangesanjean eeceet, eens eas apieteee,pogo yey pos scfiymedbyconstant experience.Te ee wow heatte | ov ems a ‘tovation anddepression ofthesea,whichsucceed seater eraterendeet opiie oc Letter. a, 0 LETTER LXV. ‘ThesemeSubjectcontinued. . Yoo tae ert hennanalain inthestateoftheearth,butinsofarassheactsReaually onitsdifferentparts.Thereasonofitis, trouldboequally stmctedsandnocoangeisthe Eeeenmeerae mecnn Grslmarr fallyattractedtoitthan&bodyat©wouldbe5it*walfapproach itthen,withgreaterveloiythanhia last:henceitnecessarily follows, thatthebodyyee ‘moon;asifthereweretwochariots, theoneatA,Soinbecrraereare eae eo ec Acestts RESThietierra fromthecentreC. PointSSeahomGncotof soSEoaSeraea ioe: os iMeera comemates Semele enteeasach sereemennin eeetaerae Sees eSaewhichareimmediatelyunderher. Lakwsnow,Thewinn,stteadto2bodyatP, m ‘FLUX AND RRFLDX re ye etSestrmatencaria ts ouat RAY aerate ane eiantneuerae Reid acres araFEtrae tatapefon itetetaperrePrrorerpoeetrshereitesPomeEelpeiceaitareeraes astnnybe,hewaler mntTwcoualy whenheaoanieaad Pactra saeiniregemeas ‘thehorizon,oratitsgreatest depression underit.PEE ees eeeSiterairs atcha arate paraaren cuarrat ScieWAGgitserope coseEenLetekkeetee ina eiect Rous (ons ieee cea, aerated ‘thepoint most distant under thehorizon, sheexer- EE dereeionecier wate ethane ins Gaia cee Gemtuen Sues Genes>Las a or THE as. 293 fivemunutesfromthefrstperiod,shereturnstothe ‘oaith, raising thewater eon thepreceding day Andthisisconfirmed byuniform experienee..“Thisalternateelovationanddepressionofthesou atintervals ofsixhoure andeleven minutes, having such aperfect conformity with themoon, leaves Us‘aproomtodoubtthatthefluxandreduxoftheseaAtecausedbythoattractivepowerofthemoon. Ttisaremarkable circumstance that sho acta ‘qualyontheseainraisingit,whethersheiatherExampotunderit."Thusappotedetfretve ‘pint underit. ery ‘rangeiophilosophers, whoimaginedthatthemoon Imuntprodce underthehorizonaneffectcontrary tothalwhichsheproduce wheninthezenith. But You seo clearythatthemoonproducesthe’same ‘tectinthesetwodiametrically oppositepostions 2Ihavedemonstratedinthegureabovereferred 10,attheaotofthemoonithesameatAandaD th October, 1700. LETTER LXVL ‘ThesameSubjectcontinued. Faoxwhathasboensaidrespectingthefaxand refxofthesea,youaustbesensiblethattheaye temofNewton whichIhavesdoped, iedeciy contrary tothat ofDescartes, According to Tast, themoon exercises pressure,andtheweemust subsideatplacessituateddirectlyunderher:but,fecording toNewion, abe actebyattraction,and forgenthowatertoieaftheeveryplace, Experience, then, must determine which ofthese ‘two systemsistobereceived.Nomoreisnecos- tarythantoconsulttheobgervatonsmadewithre- specttotheocean,inordertoseewhethorthewater tntawametmereheenth sortseebatts Bes CoaneEeete :a =Sirens eriees patae easiestbars ghey ealaeetae ee eeeee SecertmeeepacSa festasietefenpee onze ‘ireysten‘OtDescartestathey Peeteto! Simei ce 2 eee eS icc a SeSeahFigenwrites Showhowthemoon,beingovertheheadsouran|tipodes,canproducethesameeffectaswhensheis"Bcperisnce,provestha’ihe state"ofthewateratAisthe7,36 serieatbe ieehbrr as Petty podesatB.Theeffectofthe ‘moon,then,onthewateratA,os Seseid oe {stowthtwhenheshoonea Geeseif'shewereatN,itisimpossible aSESE EP eg ts== oo van es ms Intetemofstnonecon |sbieGansakearate maa alter emate PRGIW,2aOTTTiespat«prcdngeenbe contentsaseiagerac, Sune Edens matty aedSPSeerie eanei SrscerecgvalyRattiSeshoe Sere dataneener Tabata Sie enonaa8 willproduce,whereshearrivesintwelvehoursand.ei alia there e's ieSearTeste tetonatne Bid Pi alyaae eCott eieae! oe etSepa eee Stary ime Frei otpaa’ dilate cSNOP SARS NN ee eSeSoe et tah SerSeeCySSTRE ly sn wre Tet Raa ray rest atta ety eatery at eR eticbyniga 228 Mixwmseror‘waterfromotherparta,someofthemverydistant,reinstates,‘ccumulationoftsufficientquantityofwater;iti, then,verynaturaltosuposethathighwateratA shouldnottakeplaceforsometimeafterthemoon:haspassedoriN.‘hiechervatin,thereforeie 0farfromoverturning oursystem,thatittends‘stronglytoconfirmit "Thereisnoroomtodoubtthetthepowerwhich hasatendencyt0raisetheseamustprecedeits greatestelovsion,nay,thet2considerabo.time Fastintervene,othewatrustdowtiterfrom esveryTemnote, that reWatermutbelow,while‘yighatkeIfthewaterhastopasethroughstrats,oFhasitscurrentotherwise obstructed, highwaterwillbestillmorecarded;andifintheeanitshighwaterat {twohoursafterthemoonhaspassedMotN,itwill‘otbeattheheightinnarrowandboundedseasfor‘threehoursormore:andthisperfectlyagreeswithdailyobservation.11thOctober,1760. LETTERLXVIL.‘ThesameSubjectcontinued.Yrisnolonger,then,amatterofdoubt,thatthesusandrehash eucanodbythetractiveowerofthemoon.Butthereremainsonedificulty| poretoberemoved:Whyisthemotionofthesea ‘uchmoreconsiderableatthetimeofnewandfal ‘oonthanatthequarters IftheToonwere hearerthe earth whensheisnew,offall,than Thyinthequeenarherpesintywold in nyher‘proximi interesseherpower.Butthoughthemoonapprotches fheearthsometimes more,sometimes teas,thedi | ov Tae ata, cd ferenceisalwaystooamalltooccasionachange90 considerableinthefuxandrefuxofthevea. ‘Besides,thisdifferenceisnotregulatedbythe nowandfallmoon;anditmayhappenthatthe ‘moon,intheintermediatequarters,shouldbenearer tousthanwhensheisnoworfull.WemusthaveTecourse, therefore,toanothercausecapableofin-‘creasingthefuxandrefluxoftheseaatthenew4ndfallmoon,andofdiminishing itattheinterme.diatequarters.‘Thesystemofattractionshowsusatfrst,thatitintheactionofthesunwhich,joinedtothatofthesoon,furnaesacompletectiontoallthephe-omenspreventediowbytheMuxtodrearofthe oa. allthatIhavesaidrespecting theToulpate tothesn,whowstialspower iesun,w sitslikewiseunoquallyoaallthepartsOfthearth,accordinga8theyaremoreorlessremotefromhim.Theattraction ofthesunisevenmuch,soreintensethanthatofthemoon,sitchiety regulates themotionoftheearth,andcarriesrounditaorbit.aidepents ontheinequayoftataction,with ea,it‘ontheinE wit ‘elation tothediferent points Ofthesurface ofthe‘earth,whicharemoreoFlessattractedtowardsthefsthaniacentro-eshavealreadyshownYou, {nexplainingtheeffectofthemoon.Ifalltheparts ofthoearthwereattractedequally,nochangein theirmutualsituationwouldtakeplace.Butthough thepowerofthesunbemuchgreaterthanthatof ‘themoon,theinequality, withrelationtodifferent‘partsofthoearth,isnevertheless amaller,oa accountDfthegreatdistanceofthesun,whichis400timesfartherfromusthanthemoon.”Thedifference ofthepowerwithwhichthecentreoftheearth,and‘thepointsofitssurface,areattractedtowardsthe‘ean,isthereforeverysumall;andfromcalculations a8roxaxpmaruoxovTureri.ctaallymade,itisfoundtobethreetimeslose,Dearly,thanthatofthemoonuponthesepoints:Iwasscopeofcuumingteaxantreeof ‘3ax thepeabuttwouidbeaboutthreetimeslosethan thatwhichitheeffectofthecombinedinfluenceofthesetwolominaris.itiideaatthefundraofte eaareproduced erof= themoonorthatihrearerellytwotidesooee-towed,theonebythemoon,theotherbythesun,{tndcalledthetunertideundthesolarde."ThatOfthemooa,nearlythreetmeagreater,followsits‘motion,and'fromovedaytoabotheriarotardedthree-quarters ofamhour;thatwhichfollowsthe ction‘ofthesunwouldcoostantlycorrespondto thensehousofthedayiexitedalone,ortherewerenomoon,Thesetwotides,the’ana fodthesolar,togetherproducethefxad.refx ‘Ofthesea:buttstheoneandtheother‘akethewatereofthsealterastlytohseatfall,whenithappensthatthesetwo’causee”coointlymaketheteariseandfaltsNoxanrefiexteretemuchmoreconsiderable: butwhenthooneteuranehnenandhetbloveia‘sameplace,whentheyactincontrarydirections, theonevilthenbediitnished bytheolor,and thelanartidewillbeweakenedbythesolar,Ae-erng’ax theasetidesansorcheck,each ther,thefuxandruiyxwilltheabemoreorloss onaiderable.‘Now,esatthetimeofnewmoonthesunand‘econireinthesamepartsoftheheaveon,thelt‘Sdectsboingperfectlyinunison,thefaxandredexttavtthenbe. ‘boeingequaltotheeumofthefotides,‘Thiswilequilytepoestuetine“offalmoon,whenthemoonieoppositetotheeutytsweKnowthatsheproducesthesameeffecthoughshe.beinapoint.of¢hoheavensdames j UNIVERSAL ORAVITATION. 290 callyoppositetothefirst.‘Thefluxandredox thanatthefrstandlastquarters. Forthenthe |power ofthesun isexertedtolowerthewaters,aid Thatofthemoontoraisethem.Iisovident,thore- fore,thatattheseseasonsthefxandrefhixmost be Teas considerable: and sctual observationcon- firmsit. :"mightbeslfurtherdemonstrated bycalcul. tion,‘thttheeffectofthemoon,oroftheeun,1 somewhat greater when these bodies are attheorequallydistantfromthetwopolesofthe globe:whichHagensatthetineoftheexuinoxee,fowardstheendofthemonthsofMarchandSeptem= ber.Htsfound,to,tatatthattimehetideare strongest.It follows, all doubt, then,thetes,orthefxandTofuofthese,are caused bytheattractive power ofthemoon andof thediferentpartoftheseaThehappySepang: ifferentpartsofthe4ea. s tionofthisphenomenon, whichhad0dreadfully perplexed theancients sscompete confirmationsystemofattraction,orofuniversalgravite- ton,’onwhich isfounded themation ofaltheSTUOctober, 170. LETTERLXVIIL More AccraofthDiptera portalsAcrothDaprepeting Hvms given you ageneral butexact idea ofthepowerswhichproducetheprincipalphenomenaofde"enverestadonwhichaefoundedthe rotions ofalltheheavenly bodies, itisofimport-teefoconsiderwithmoreattentionthovepowers an) paverssuarscrare ‘which aretheprincipal points ofthesystemof Sranen,aca iiaa,iesme tuallyattrecteachotherintheratiooftheirmass, godratelytotelStance,Inepnormityto2 reedThe a ‘mannerin whichmoetofthephenann‘nmalweareae founinforproventattiapponitionifoundedincoth;sodthattheattraction,whichdifferentbodiesexerciseuponeachothermaybeconsidered‘221montundoubtedfact.Ttnowremainsthatwe {quire ino the causeoftheseattractivepowers; betisesateelongeratertotheprovinceofIpetaphics. thanofwaaibematcn, Fdave‘not thereforefattermyselfwiththeprospectofabeo- Intmecinteprosecutionof ‘Aaitincertainthatanytwobodieswhateverareatiractedtoeachother,tequestionia,Whatisthetauveofthistiraction .On'thispointphilosophers fevided”“TheEnghalsathtattraction it'spropertyeesentialtoallthebodiesinnature, todlatthetebodies,hurriedaloogbyanirresst- Blprommatytndnlyoeproncyantthey werei ng.‘iheponer ‘snaiderthinopiionaab warandcontrarytotheprioofrational BBlcopiy. eydontdenythefacttheyven ‘amitthatpowersexistwhicharethecausesOftheFecprocal Tendencyafdinetowardseachother: Estoymaltatatnyaetorigntothebodiee: thathaybongitheeterorthewalesaier which them,andthatbodiesmaybeput Thmotionbytheether,justasweseethat@body Hlsteednigfnreotvncoverpreeiony | Thine,accordingtotheBretthecauseof theattraction rnideainthebodiesthemselves,and fsessentialtotheirnature;andaccording10the| Iaetitisoutofthebodies,andintheSudwhich| survoundethem.tothiscas,thetermaltruction| | ‘UNIVERSAL GRAVITATION. 21weetimran,endomthoaytht oubeforeachie apne oma eee feelnorgiveofeace,provideditisnotpretended DOSEStanmrrahdSoetperie byroidallconinionwhichmightroomcarmsret centon icighet sh al.com, oughtersi sasheseresrorencentua shhcate acta ieeeanthganmaneofsenhogmit Pageit herrtyeoof wetessas ray ‘nin, tat allthee wed sukegcsauay ss,tsalhagald fpbcorerecenla tey rs erat, NET iielayaa anhntsee Soe htetechihasewe felen Fceredpore,mumsools ae ce rms rieet, impleaayomaratists spn wnat i opin son cateeroacneennhaonhy,weygencealratobreatas ne eee Sctreee Bopp peer ern smatithao Fee eecareonadate coranngtegngnetorene,de SeaAareicesoreanges Heleee at ee ocean ok ptt pore nee baaConte ate ciently pbsonbdtckreed leatapaail poten woh eer Za sms currenvodhetweetonyoyetent2 srlhdeedsuebgieeas ees ieaesli vesnatTaslecseer eae Poe prepathawewclmetergPomDieseaner,gitreSpdHathereaaeee Begte,cer me aoace peed rap inetd‘eribethemutualattraction ofbodiestoanactionSigma cen wf en ate‘manner ofactingmaybeunknown tous,ratherthaniaotictayocraogier Eomwieeemtienreiteecct seas temacle Soe gates Recreate Areassce a orratherwasanattempttoconceal ESE kg erpekrs outsceraereene freienmecalaigin wat gateEieainesortacetoes Shy,attrection‘oughtnotTobeconsidered inthe ccm, aeratenseisemg ‘Sharingtoteaonng,apeebearsokabe SCNTSsefeartnsuneytongteeGoalstapertensbos Se erases MATURE AND EAMENCE OF noDuES. 288 LETTER LXIX. NotureandEssenceofBodies;orEstension,Mobiity, ‘endImpenetrabitity ofBody. ‘Tax metaphysical disqusition, Whether bodies maybeendowedwithaninternal owerofatract- ingeach other, without being impeliedbyanexter- wlforcescantbeterminatedtillwehaveexam ‘moreparti ‘natureofbodyingene aL.‘Asthissubjectfofthelantimportae,not ‘nlyinmathematics andphysics,butineverybranch ofphilosophy, youmstpermitimetogointoamore articular detailofit.safiatitinanked, Whatbody1Howeversbeard estionmayappear,asnooneisq thedideronce'betweenwhatinbodyand.whati Rot, itis,however, dificult toascertain the real Sharacters which constitate the nature ofbodies. “The Cartesianssayitconsistsinextension, andthat whatever isextended isabody.. They clearly un- eretandthetextensionhaninthisasetreodimen: tions,ndthataengldimension orextension in fengthonly,givesonyaline:andthattwodimen- sions,lengthandbreadth,formonlyasurface,which stillisnotabody.Toconstituteabody,therefore, ‘wemust have three dimensions, and every body ‘most have length, breadth, and depth orthickness;inotherwords,anextensioninthreedimensions.Batitisasked,atthesametime,ifeverythingwhichhasextensionis«body.‘ThismustbetheaseifthedefinitionofDescariesbejust.Theidea:which thevulgarformofspectres contain exten- sion; itis,however, denied. that. they arebodies. ‘Though thieideebepurelyimaginary, itserves.10rove,however,thatsomething mayhaveextension‘withoat beingbody.Besieg theteawhichwo py sarensAxhaveofspacecontains, anextension.Tritreednsensione itelite,evertoloe, Tatpacealongsot«bodyonlyfarses BicewhichbodesoccupyandHatteappoetntalltenthingswhichaeatpresentinmyapartment,arandeverything,were EnnihilatedbythedivineOmnipotence,therewould Temainsillinthespartment.thesame.Tongth, breadth,andheight,butwithoutabodyint.Here, then,itthepossibiltyofanextensionthatshall notbeabody.Suchaapace,withoutbodyinit= Gategractn;«veo,henereenwit 1maylikewisebesaidaccordingtothevulgareranatcecea {Seadeno iasunfoconte{aisethatteSolitoneftheCaieianieaot exact.”Butwhatmoreianoceasry,besidesexton- {iorthepony ofboingtnmotionfor, ity,oFthe inmotion;for,thagaolyteatswhoremayeteconesPiomoveitprovidedibepowersappliedto Bitereaston,”Bytsopedencnted rom the’claseofbodies,eawe’see.thatspace,which ‘onlyservestoreceiveboties,remainsImrmoveable,fEnisvermotiontebodiesThacontainsay Itislikewise saidthat,bythehelpofmotion,bodiesaretraneported fromoneplaceto.another Byphekiearenenertndtatheplaces apaceremainunchangeable. EoweferwitiherocuanwischIhaveshove. sedightundockdybenord,andactlyfx fo,aitfollowsthemotionwhichcarriesroundtheearthitself;here,then,isavacuuminmotion,[email protected], too,be~ wescme Sainpromi sarees 2realbodyfomsimpleextension,ofromaspectre. Peer pea ener Fro'bodies ondoccupythesamefacestonc. Eposceettie’ Sista sah“Beeeepengtota casilymovesBrugandthroughwater,which Sead Ebbets mereera ee Sa ee eeeEero cimace aaterarenaitiesa Eirenerve ia Geiatewonionee sitiat beaiecteleatmeeetea Sonar emanerenieete So eres es gear aa,Se er Bee et inceiabeolieynecseary tuetheBodywht ‘Seesoreo eee“Thinihewe ‘wemustaffixtothetermimpenetrability. sioe S$960 mermceraunusr oFpéouns. LETTER LXX ‘Tasinstanceofsspungewill te dusedteenotjection tetheinpancbebityot bodieswhichplungeitowalerappearscompletelyPeodtnndbytBttheprinoftheange Eevoryfarrombeing00,2muchamannerenthatneparleofthewater'should_ occupythesame placewithoneparticleofthespunge.”Weknow {atspungelaaveryporousbodysdthatbefore ispatitoheslrporesaeledwiay tonuharern poreof SpungetheairIeexpelled,anddscngegee elt10penetrationtakenpcentheoftheirbythe no08place,pel elevaieweityashiaaleape InakesiaescapefromtheplaceintowhichTi:tenyageneralapdessentialpropertyofall a,thea,9genebodiee'to°be impenetne; and.consequently theEe.ofthisdeationtatbolialar Gon ingentrlle extension 9leaureextendedandimpenetfable,butlikewiae Neippealy aatwhichattesameSeex Impenetrableisbeyondcontradiction & body.Vacafsscoringexeicedfomthe clamofbain;fnihgaghibaexten,ans penetrability; and ‘wherever.wemeet.with& ‘vacuum,therebodiesmaybeintroducedwithoutTintinganythingouofhsplace. ‘Weustattempttoremoveanotherdificuty raisedaguinnttheinpenetrabiity ofboaien.There Ere,eaytheobjectors,bodieswhichadmitofcom ‘rowanintowsmalerspacea,frexample,wool, IMPENBTRABILITY OFBODES, 937 ‘and especially air, which itispossible toreduceIntospeceathousandtimesaalierthan what ‘occupies. Itappears, then,that the differentowofairareWedveedinhenameplaceodtat consequentlytheymutually penetrate. ‘Thetishowever, nothinginthinsfortheair tooisabodyorasubstancefullofemptypores,orfiledwiththatidincomparaby ‘more,wbie,‘Whichwecaletter.Intefrstcasonopenetration willensue,astheparticlesofaironlyapproachnearertoeachotheraccording asthevacuumisMiiiahed aintheothercaeiheterfinde ‘ofsmallpassagesbywhichtoescapeas {heparticlesofthetirapproacheachothe,batall ‘thewhilewithoutanymutualpenetration. Forthisreason itisnecessary toemploy agreater forcewhenwewantfocompresstheairmore:andifthe tirwerecompressed foauchtdegree thatitamic ‘muto particles touched each other, we could not‘earrythecompression farther,because,wereitpos-tible, theminute particles oftheairmost mutually Itis,then,anecessary andfundamentallawin ature,thatnotwobodiescanpenetrateeachother,occupy thesame place atonce;anditisincon: formityYothispinctlehatwemustlookforthe Tealsourceofallthemotionswhichweobservein allbodies and ofthe changes which befall them.Astrobodiescannotcontinuethetmotion without ‘Penetratingeachother, itis absolutelynecessary Bhattheoneshouldgiveplacetotheother."Ifthen, footie aemovingfahesameHinehene theothertotheright,asitfrequently ‘pons atbilliards, ifeach were toconfinue itsmo- ‘tion they must mutually penetrate; but this beiinnposetle, ansoona8wheycomefotouchmock takes place, bywhich themotionofeachbodyis ‘almost instantly changed; and this shock ispro- 38 orionoFDoors. ducedinnatureonlytopreventpenetration. ThePppreared= attion;andin {hisconantherealcaseofallthechangerwhich"Wienallthenechangesareattentivelyconsidered,‘refoundalways10takeplaceinorderto ‘eidsomopenetration,whichwitoaheechanges ‘ousthaveensued..AtthemomentIamwriting,1cheere thatifthepaperwerepenetrable,theon ‘oulpanerealyinowitoutwring;butathe +PaperSustainsthepreseureofmy”penmoistenedfritink,itreceivesfomitsomeparticleswhich{ormtheseletters,whichcouldnotlappenifbodies Penetratedeachother. This‘ofalibodies,knownbytheterm angryathennotonlyofthelatimportance ivelytoeverybranchofhumanknowledge,but ‘womayconsideritasthemaster-apringwhichTa- {uresetea-goinginordert0producealherwon- ders.Itmerits,then,anattentiveexamination,in ‘orderthatwemaybeenabledtoexplainmoreclearly thenatureofbodies,andtheprinciplesofeveryspecies ofmovement commonly called lows of ‘metion‘95thOctober,1760, LETTER LXXL OftheMotionofBodie,realndapparent. ‘Arsbodiesareatrestorinmotion.However +evident this distinction may be,itis almost impos-thlejudgewhetherabodytintheonotator intheother.“ThepaperwhichIseeonmytableveemstomereallyatrestbutwhenIreflectthat‘thewholeearthismovingwiththatastonishing . omtox oF ootes. 20 locity which Iexplained ina former Latter* miToure,trytable,andthepapermustsbeclutely betured along withthe enme raplety.” ‘Thus everythingthatscemetobeareethasinfealtythesame totfon asthe earth‘Wemustthereforedistinguishbetweentwoinde ofreat;theone.absolute,theotherapparent.-Ab-folate reet takes piace when s.body’ Femaina con- tantly ‘inthe sue place, notwith relation tothe ‘arthbutwithrelationtotheuniverse.Ifthefixed stare remained always inthe same place ofthe tn‘erve,theywouldbeatrest,houghtheyseemtoInoveveryrapidly;butanwearenotcertainofi, tremontnotpretendtoaffirmthatthefixedstars Breinaalateofabsoluterest “Abody1ssudtobeinastateofapparentrest witen'tpreserves thesameaituation oftheearth, Beisikewive tobepresumed thttheseterms,rest and motion, have been introduced into oSat'yetnerappenrtsces anathta’ng senve Lair, without hesitation, that mytable inat-Teataswellanthewholeearth;ndthatthetuntdthefixedstarsarenmotion,andthat8 Fapidmotion, although theyaroreallyarest.We ‘hould, therclore, beascrbing strange and purelytuetaphyeal ideasfothesecipressions, ifweutedeedythemaerbmanandit ‘ploy, ansome’persons do,passages fheHolySevrestoprovehattheearthak "EaSpmge isriedfrporalwwe,andphlloao- isformedforgenerause, reunderthenecesslyofformingapareulat forthemecives:“Asweareincapeblet0 Sud ofabnolate rest, itivery natural forusto ‘ZenkerthovebodiessaatretWhichpreservethe seme situation relatively totheearth, a»its very ‘rotable theinkabiants ofother pants LXewis tae. :m0 onionoFnoptes. fomthetjdgmentofrtromthosamestatin elyibthisrespociveplanet, "Weobservthatnavigtor,cousinanatreat theobjects whichpreserve thesamesituation rela-tivelytothervest,andthatthecoustawhichthey‘incaverappeartothemtobeinmotion;ndnooneibisorRingfantwiththetunighe common‘modesofexpression. “Thereis,therefore,a EtfrnceSevenrstandsoirealorede: tndbetweenreeandmotionapparent,oFrelativetoabancomerathetineeiateofre, ‘théaghperhapsitmaybeinmotion. ciplesSrlawsofmotionrelerehieytothesbealutsala ‘ofbodies,thatis,totheirrestoFmotion,realorthsolute.” Inorderto discover theae laws, oebegin.‘ithcomieringabodyengyandsbtracidlyrom "Thinhypothesis, thoughitnevercantakeplace,iinrealityr tosaint‘usindistinguish ‘whatinoperonByienaaofolyro EatwishotherBodinaocapableoperating‘Letabodythenbealone,andatrest;itmaybeasked,WillitcontinueatFeatoFwillitbogiatomove!Asthereisnoreasonwhichshouldinclinetomovetoonesideratherthantoanother,iteConcledthatwouldemainalwaysatresThe faethingntLappn_ontheeapponion ‘existenceofotherbodies,providedtheydonotact {fhebodyigoetionHencerenathifunda ‘montIw:Whenabodytsncein0lateofrest, andnothingesternalctssponitwronanahoays Srelatsatesondifsbegintomove,(hecouseofmo-Signwouldbeoutof0thtthereisnothingtntheitselfwhich4scapableofputting1inmotion.therefore,weseoabodywhichhasbeenat eaogitomove,wemayrstauaredatthie Totionhasbeanoccasioned byanexteriorpower;tethereinnothinginthebodyitselfcapableofput AoTIONoFBootes. um fingiinmotion;andifitwerealone,andcutoff from allcommunication with other bolies itwould romain aways arestHoweverwelloudthislawmaybe,andhow.everalitledtorankwithgeometricn truth,thersSiepersons litle accustomed toprofound inveaign-Hon?whopretendthatitiscontradicted byexpe. Hence.‘TheyallegetheexampleoftreadYowhichnoi append thesaneiFoatta the moment that the thread iscut, Iticertain, faythey thatthe ation bywhich thethread sentitettofmatingheanamoreenn mustfallbyapowerwhlchleproper03 iteltandinternal proe “Thfactiscertain;buttisevident,atthesame time, that gravity iathe cause ofthe "descent, and Dotanintefnal power inthe stone "They say furthor, that gravity maybanintrinsic power’ altiched 10the ‘nature ofthe stone; om RTS mu rmased thatgrant iprodaced ier bys subtle matter orbytealtacton ofthearth, Inthefrstcase,itcevinly isthatsbiloBiterwhichcameiedocethesone coond, whichappears favourable 10our oppo- nents edawith nopropriety beaired thatthottonedescendsbyanintansicpowersitinratherEtat ht hexn etch Droduceethedescentofthestonebyitsafracuive Power, forifthe earthdidnotexofweredeprived Erisattractive power, theyadmitthattestone ‘would not descent, Tis certain therefore, that the cause ofthe de- scout doesnot reside inthe stone itself: the cause ‘Shen isahyaye extrinal, whetber itbointhesabe Iatier orinthe earth, supposing ittobeendowed‘withanatractivepowerasthepatisaneofatzso-on pretend, ‘Thi dificltybegremoved,thelaw ‘hichhavelaiddownsubsistinfllforce—namely, Tafabodyonceaeawilvayeromansowtete us orwomton. leesitbeputinmotionbysomeforeigncause,‘ThisTewtustakeplace,providedthebodybasbeenatTesta giant thooghwasfaoonieInetiately before;andwhenonceTeducedtostato(Ofreit'wilalwayspreservethatstate,nlesssomefae come IntervantoptgainInmotion. ‘Thisprinciplebeingthefoundationofallmecbanics, itwannecensaryformetoeatablishiwithallpos:snpecan ‘October, 1760. LETTER LXXIL. (OfUniform,Accelerated,ondRetardedMotion. 1nrrountothecaveof«bodyplacedinsach#manner astobave noconnesion with any other Tot ussuppose ittohave received some’ motion, from whatever cause; iremains thit weinquire,Wharwilatereadhappenot?Wittcontone Ielmove'orwiltsudienlyrtumtastateof reat;ofarsometime’Youmustbesensible, {hatthiinaninquiryofsomeimportance, and-thet Allourreearchcerespectingthemotionofbodiesdepend upon it.Let useximine it,bymean of ‘eksoning, weareable toresolve it.“Abodyieateataxlongasitandallitspartsremaininthesammeplace;tnditiinmotionwhenfhatbody,orsomeofispartsony,pasefrom’onelacetosoother,Now,{nereaze’iwothingstobe Seancntedetonate elo. ‘Thedirection tetheplacetowards whichthe body incared, andthevelocity isthespace,greater ofFsTroighwhiehimovesnaeratine, ampermuadedyonhavealready justerideasofiia {tarcondcoonieatbyhemos!tplexe nation. Tremark only, that aslong asservesthesumedirection,itmovesin8straightae ornono. Pn sandctproey,ssong280ttymores2 |phraeaaty sone 2etynares at ‘whenitmovesinacurve,itiscontinually changingeee‘abody,then,Fig.36,movesinthecurveABC; rpm, hs when ia 4 crction ef eal Ho A3 when itisatB,itsdirection isthe small line Bd;SEatogdon6eeSELhealteOattecoalet bbythestraightdottedlinesAL,BM,CN;anditwilbeaffrmed,thatwhenthebodypasesthrough fediecionaiewentoeteen atA,itwouldmoveinthe tlineAL.ItisiearhSethpeeaeSt See eco coe hte domBMandCN. bythestraightA,odyeerste umevlociyinitsmotion onDaypierstgvamealain. ots ine mores houghevnceco ‘example, ifabody moves insuch amannerasalwaye Person heeleanor aua orworn.motionmiform,Ifanotherbodyproceedstwenty =feetin'ssecond,itsmotiontoowouldbeform,Bevisvlcwoulbewienrototaof‘omwhaThavejotaudofteuniformityofrotioniteasytycomprenend whatsnotuniformtmoton’forwhenfhewlockyoftbodysnotequalEXnodonettern,Whenieyetyfs coitemotionin cedlorated;andwhenitiscontinuallydiminishing, sreuyieretadedIntislatcane,theveloc Beysmetoevenedtomechdepresatit Bodyaltngcmeoaofes, vingmadotuesremarkeonthevelocityapddiacofmovingSoinfantthecanea solitaryboty,which1suposetobeptinmotiontyanycaveswhatever.“Resoonanifhasbopuntooveimahavesouredacnadrs,nd feriavloty:andthegeeonisWilfer. locerwiltwdorgosomeaor "We Yelocifyorwilomestration’“We anootstmthatitwilbereducedtoateofret ft'aninstant,forinhiscaseicounothavehad hymotion,almotion GarlionhoweverhortNow,anlonganhemotionTartsiincor‘fntty imposefoconceivewhyhebody atret conceive shouldgooutofHsros,toooesideraderthan©thesandntngcomesophotex oniflowsthattheodytnquestionwilalwaysTHTproceedinuralinewhchisugrestatep inewhchi Tinietowardstedeckerofthequstion n?Fife aliahavlofte F peakcannot ‘a caemnorneeorahno Seasoncen‘ange,“Henceiconciedthat'sbodywil ‘iweyecontinue10movewiththesatevelocity, LAWOFMOTIONANDREST.=MAD |andinthesamodirection,orthatitwillproceed | SOntnaaly isthearecton ofa-ring with atever, deviatingfromitand,alwaye, withequal speed.Thismotionwillbeperformed,then,alwaysinastraightline,andwithanequalvelocity,without‘ever being slackened orretarded; thebody, there- fore, wil neverboreducedtoastatofrest "Whathasbeensaidofabody,whichThavesup- posedsolitary,wouldhappenilikemannertoour oboifnootherbodied. anyintoenceapon it forthenitwouldbethetamethingasiftheydidnokintThequstion,then,rensived.“Abodyin ‘motionwillalwayapreserveitinthesamefdwiththeameonuslemsomesera ‘causeinterpose cupable of altering its motion.Fong,therefore,asbodyisnotsubjecttotheationofsomeexternalcause,itwillremainatrest,ifitfanonce:beeninastateofreat;orwillbomovedfnthedirection ofastraight line, andalways with‘thesamevelocity,ifithasoncebeenputinmotion; andthie isthefrat and principal lawofature, on“hichthewholescienceofmotionmustbefounded. From itwededuce atonce this conclusion,thatas ‘oftenaswosceabodywhichwasatreatputinmotion, or1body moving inacurve line, orwhose‘Velocitychangesitiscertainthatanexternalcause{ets upon it.Nochango canpossibly take place either antodirection orveloctty,butwhatisthe ‘operation ofa foreiga cause. atNovember, 1700. LETTER LXXI. Principal LasofMotionandRest.DisputesofPhi ph ontheSee ee Wirm whatever solidity this principle isestab-AishathateverybodypainmationGoatinesto 6 ‘PRINCIPALLAWOF moveinthesamedirection, andwiththesameve-aprestcenteee tyanesconoGiSeaiaearn ota dyeranerr secreomenmscmenwe Bere SA rene ele pe decry re sd nt oepears nec eaecaypineal Drietopnweeoonnn cro,pieageiaeret rere gcettree +when'sbodyisputinmotion,ithasatendencyfromemcee nee a irae hee see err, aaBeyehot,eraseova. BaeSee regeeteyeySeater eeme moa paresiswaate otfdamnteontnicksun poewveces ramos Hayarenemeasiner i Tg mbitoeteheSea Pareahhnyaime, ey‘preserving itfromanything.initsownnature,that,Poe a ee‘Youtmtnvecile, hatithicontaininjot eacaathe cnetwpfencecymes ees ton,onzepufinmotion,mustalwayspreservethe inscmatinsrrchange init,Thus,intheexperiments referred td, xomON AND nest. ur hadtherebechnoexternalcausewhichtendedto |strthemtin,weshoohavebeenunderthe‘tbandoning ourprincipe, "Betiwoattendoerthingweablfod.smanyobtaceeapponed vothemotion,thatwened towonderitshoul!be80speedilyextin- fInfact,itifratthefictiononthebilliard.ambsdrencethotradbnggun’te‘lots vancewi ath.‘Again,theai,beingasubstance,ceuneslikewise8resistance. capable ofdiminishing the motion ofTodies."TobeconvincedofthisyyouhaveonlySGmoveTourhandrapilytroughhearIe evident, then, that in thecase ofthebilliard-table,itisthefriction andtheresistanceoftheairwhich ‘counteractthemotionoftheballandsoonreduce itto'a sate ofreat. ‘Now, these causes are external,anditiseasily ‘comprehensibio.thatbutfortheseobstacles.the ‘motionoftheballmusthavealweyscontioned. The ‘samoreasoning.isjetomachinesof Kinds,inwhichtheffietionwhich‘otaonthedif- ferentpartsis20considerable,thatitisvisiblya eryallclentcaseofsoonreducingthemachine Torest. Having, then, discovered thereal causes which ‘produce,inthecasesalleged,theextinctionofmo- ‘tion,andthatthesecausesareexternal, andnotre-+shdontinthemovingbody,itievidentyfalse,that Bodicehaveinthelrntar'propensty 2rest,”Our principle, therefore, subeiats infll force, and even Aeguire ahional rength fromthepreceding Ob.Jections. Every body, then,always preserves. thetmotion‘which,haoncereceived,tnlosforeign ‘cases interposetochangethedirection,orthevel Sty,orbothatonce,AndthusweTategotdo ‘onephalanxoftheadversarieswhocombatourprin- the otterismoeformate,fortheyar0aes ms LawOFMOTIONANDREET.‘thanthecelebrated Wolfianphi.‘They.dofatintelopniyocarenganesootciple,aay theyevenexpressmuchrespectforit;batthey‘anceotherswhichdirectlyopposeit ‘Theymaintain,thatallbodies,invirtueoftheir ature,aremakingcontinualeffortstochangetheir statechat,whentheyreatret,theymakean efforttomove:and,iftheyareinmotion,makecon- {inualeffortstochengetheirvelocityanddirection. ‘Theyallegenothinginproofofthisassertion,except‘certaincrudereasonings,drawnfromtheirsystemof ‘metaphysics, whichIshallbereaftertakeoccasionto laybeforeyou.Ionlyremark,atpresent,thatthis ‘opinioniscontradictedbythe’principlewhichwe Ihaveoofirmlyestablished;andbyexperience,which ‘ninperfectconformitywithit : «In fact,ifitbetruethatbodyatréstrémains, invirtue‘ofitenature,inthatstate,itmustbeun- doubtedlyfalsethatitshouldmake,invirtueofite nature,continualefortstochangeitsstato.Andif itbetruethatbodyinmotionpreserves, invirtuefitsnature,thismotion,inthesamedirection,and‘withtheeamevelocity,iisimpossible thatthesameBodyshould,invirweofitenature,bemaking’coa-Aint tochangeamation, "These phil ‘ailemptingtomaintain,at taesametimesbetrueprincipleofmotion,andthet ‘ownabsurdopinion,havefallenintoselt-contradic- Son,andthorebyeubveried terownsystem.“Ia ‘thereforeplacedbeyondthereachofdispute,that ‘ourprincipleisfoundedintheverynatureofbody, fandthatwhateveriscontrary10itoughttobs beninhedtromsoundplovophy:andthissameprin. cipleenablesus1Cleariofcertainsubiienia "Tieprcinotacomionlyexpressed pleiscommonly inthetwo followingpropositions:First,bodyonceatraf ‘willremeaneternallyatrest,volesitbeputinmotionby ‘sameogtrnalorforvighcou? JyAbodyonce INERTIA OF BODIES. 4Obhmationwtpreacrt, saSt seenraceteaecode peLarecteternenn eernethfonmcovcletsthenistionofthowholecloseseecoeieet eae verrexx. OFtsneticofBodOfPe dnrymehtdy0fagottrt solsBytaNr,ete eeeeaEmeregrasen, hs egw gre ese Soo te mee ge oi pepper ecirrtiry sete pon mere Faery tatoo inkrdnedo ‘thepurofexpressingmoresuccinctlyourgrand iemepergelexrnang mermcaowand rae a rear ay otote wees te a eae aeaets Sareeatt ey ee ao peeen te meg ht 6ty cr mathe by ype eierdeeenerecoaaaGh eit pore rancor mataaeetneraee, nae hesae sii,hughieera remark,topreventthepossibilityofconfounding Siegfovndbeanal reer cheap gg ih eo aay eel war cae emcee te razFUTnanatheyoecompetse 290 ranrisoFnovins ter,havetheofremsininginthesame Baiaiftheyfenotdrawnoutofibycomeexter alcause,Thia,then,napropertyfoundedon theatuofbodies,bywhichtheyendeavourtoPreservethemschtesinVAssanesteve,whethorof Festormotion,“Thisquality,withwhichallbodies ireendowed,andwhichiscosentialtothem,iscalled{ordaanditentersasnecessarily intotheirconst-ogrestatiwouldbeimposeileforabodyto segs,ta efor8 "ThsorawanBvtiirofocedinto philosophyby vain theewhomuintavedthetaGodinLavePrope, iyrnTheyonaoed,odynomewat eveningindolepero,whopreterrstSex ‘rion,andascribedfobodiesanaversiontomotion, farmsureeiguyingmaitosamengog. ‘awrtie camethingagece‘Butthoughthefalsenessofthisopinion eensincedefected,andthoughiticerainthatbodiesremainequallyththeirstaeofmotionasinSeenyorthetrtranbe {ained,to donateingeneralthepropertyofallbodies {ocontinueinthesamesate,whetherofTestorofTheexactidenofinertia,therefore,i ofinertia,therefore,isarepog- nancetoeverythingthathasatendencytochange {hestateofbodionsfor_an8body,invirtueoffx htare,preservesthesammesateoffotion,oFofres,tedeaanatbeLewn cutoffsbyextraeuune follows,tat.inordertoabody'schangingis Mate,ihtoastbeforcedoutoftbysomeexternal auas;withoutwhichitwouldalwayscontinuea thesamestate."Henceitsthatwegivetoths‘xiernalcausethenueofpoweroffort.Itis8termincommonuse,thougamanybywhomitit ‘silylarebaeryinperocanofvhatIhaveJostsaid,youwilseothatthe wordforcesigninsverythingthstiscapableaf nar oF oe ast hanging tho stateofbodies,‘Tao,whenbay elBsoottestopetinsiroes ie,retetnfelanwatCodyame:wiieecteePorvlocy:tngmotesteee atest anincreaseocsnonoffre. BER"oec,therefore: alvaye outoftebody Sienaie!ie"changed formshaveSeonthesaa utaeterentitayete,aesNatawinetiosceRonwrestscorapon $ Now, theinertiabywhich{bodytendstopreeerve sonttheneateeceteetebotyAead caratfreeChangesshesateofanyWaathe facelas ofoxy Seay‘mertiawhichwouldmaintainitinitheamestaterelhnaivee Bacarra ater theues ate fayoybeenero ewtheUeoftet"ibodesareeodowedwiththieinertiainaatastheycontainmatter. Itisevenbytheinertia,Babee, wathineyoperareychange ora ge eafnoyoe Eeeequteen Schcn Iweecleethatrequire enerfree 2hungetnntmrtbuy,taebaoft wechnnte segocntgonethetthegreat seeoreaaeeteeGantheonalcoe paycontRanedhatthsgnglocroumenanee,Bissendeematersenileto,tielthnttheernnceptBo ofmeasurementardthaiihosane’withs seer, whichbaycousin;weder Adakewe heuyofmndy HorassrecorotemerstetaeeTtnemae 7 . 68 (CUANOESINTEE ‘Tothis,then,isreducedour|ofbodies fnpoveral."Fit,wehowthaallbolleehaveaa ‘areimpenetrable;andheneeresultstheirgeneral property,knownbythenameofinertia,bywhich ‘theypreserve themselves intheirstate;thatis,Oar armeloyieeevealost‘andwhenitisinmotion,itislikewise byitsinertia proseploaeoechangeinitAsoftenontoets betty ee FeaeatereekTrtcas orsehstareTeptytoltocasears outofthe 7,andthisisthejustideawhichweoeOa ae te ee LETTERLXXv. ‘Changes whichmaytakeplaceintheStateofBodies. ‘Tarfundamental principleofmechanics, withthe eetcc ate Seeemasreeiy ToeAteceeeprasadeetesa”OoMeena tahSstesoedwee formlyinastraight line,thatis,whichshould pre- erara ar etleyhaeceaacamo edennlainca n einntoouctoftodyettn ofitsinertia,itremainsalwaysinthesamestate; wel‘atwettheBoaorentaos tookplaceinvirtueofitsinertia. Wewouldlikewiseberightinsayingthatthis setnoesscomyeela cor,ifanysuchexisted,thatthesepowersrepipae- ‘ rere or noniee 288 destroyed each other insuch amanner thatSeesfatesiteinwichtwouldbeimo |force acted upon it. Tf itisaked,then,Whythebodycontinuesto sporeintane! tnwer ioma ‘waaked,Why ‘gu thus Tove!thequestionistotalydiferent.”Itmunt besaid,thatfismotionhasbeenimpresseduponit bysomeexternalforceifitwasbeforeatrest;bat would beimpoesti toair any thing with er- Sint sepectitg tnegantofrktreybocease, :stytrctsoftramaiy.Itstherefore aun? “ifawfoakWoipreaedotion tneverybodyatthebeginningofheworld?or, WWao'wasibepiemoverhowewhopuhe jonadmitthem,3beginning, Tereation; buttheyimagine ttGodcresiedll touienatrest“Now,itmaybeannwored,Thatbe shecouldreatescoudimpreaeationvpn Trem,askteminmytur,Iftheybelivetobeimoreeasytocreate4bodyatretaninmoroutrhb equal regi thomnipotencefaathieguetonblogsnttotherons FEBes'wren aodyhanoncereceived mation,itpreservethatmotionbyitsownnature,orbyteEienheeamesfawhichConyTema,unl«forceorsomeforeigncause,oppons Trobsiacletoit:“Asoftenthen,atweobweryethat Eo Sorotsonteeinea Teetbopasfomove,crUtbody’inmo Honchangesifsdirection‘orvelocity,womustinitthathischangenetecauseouttthebody,totalitisocarondbyafregnfore.Fh, Seatone leftfoitselfdescend,theemunoofthet dencont inforeigfosebodysandfnnotomits tssnarethatobyexch hnIhofforeigneat,owichWegivethsamefotly annemoorSmsaettesalt safirteethe‘cfocofafrenTorosteweesPoet tinctied Jsgeometrically true,'weknownottheforeign eg eyrd Tierise feeectsBoromieSnore ates eaeeeieogee Seatnewearaecearte ‘stonewoulddescribe astraight lineintheair,andseeneraemeryea eivcnian megetweesFeo alaeeeoe Hitecaeee amevelocitywhichiehadattheinstantwhengrav ‘Butasgravityactscontinually, anduponaltbodies,caeeaseamana omaha nema fiers Sener ventamyfallingintothatbelowit.”Butthebodiespret eet . Bettina S pee oeacre saecitertiarecteracmeeeRUAcarteMiomne"ferhomentra Secale rereemeene SowyeemoretndoeDoaramBe - ‘eneoftheheavenly bodieswhichmovesinastraight sestntoetteieheee Gcaeraar cetkes efiuycgaanvnn rc Knowntous;they aretheattractive powers which Hegre eerie poe eeeaperyfo,nd stkeeatarraigne Brionihnwhertmspt ied uh fm swe ieieefhaecuEoyposnoemes seca"Thisopinion, however, thatattraction isessential vpn, ogee tatna ose tyres one Brat hy can mat poor het ieeteagoftearm ee Sein cums sera SEsSeaton eaeoe a .08 ‘sivrexoFTun LETTER LXXVI. SystemoftheMonadsofWolf. BrronsIattempttomakeyousensibleofthe truthoftheprinciple,thatalodieofthamselves alwayspreservethesamestateofrestormotion,1 {untremark,thatifweconsultexperienceoalyon thesubject,withoutthoroughlyinvestigatingitby thepowersofreasoning, wewouldbedisposed10 drawthedireclyoppositeconclusion,andtomain tain,thatbodieswayshaveapropensitytobeconowlchangingTlesaaaweanBoingi thewholeuniversebutaperpetalchangeinthetofbodeBatwohavejnownwhatae ‘causeswhic 2 we tresured)tattheyarenottobeoundinthe eiswhosestatchangedetotoffhm. "Tepincpthen,whichwehavecaabinhedie 10farfrombeingcontradictedbyexperience,thatit {sonthecontraty,confirmedbyit."Youwillenaly{edgeomthaowserragreatphilosopher, fanexperiencenotacctratelyunderstood, favelenlatetheerrorofmaitaaingatl Yodies areendowed with powers disposing them contnunyfochangeternate,ahtatWaltfaseanooed.Hesays1 Experienceshowsusalbodesperpetuallychanging therstate;9.Whateveriscapableofchangingthe thatsofbodeculledforcey3.Albatere. foro,teendowithfredcapablofchanging thoyite;veryody,therefore,imaking continualefittochange;8.Now,tisforceTongetobodyonlysofarasicontainematter;&JEGtherforeaproperyofmaterfoecontinualchangingisownoie.Maeracompound ‘mulitideofpari,denominated theelementsof | onaps oF wourr. 287 ‘matter;therefore,8.Asthecompound canhaveothingbutwhatisfoundedinthenatureofia‘lements, every elementary partmustboendowed ‘with thepower ofchanging ttsown state. oo rmjooodofparetheywoulbenolonger waren theywouldbem0 Slomenia,buttheirparswouldbeso.‘Now,2 simplebeingislikewlsedenominated monad;every ‘monad, therefore, has the. power ofcontinually ‘changing. itsstate. “Such is’the foundationofthe syotemofmonade,whichyoumayhaveheardmen- oned,thoughitdasanatnowmakesuchanoe asitformerlydid.Ihavemarkedbyfiguresthoseveralpropositions onwhichitiseslablishod, for‘he purpose ofmaking amore distinct reference,in heFeetios Imeantomakeuponthem. venothingtosayrespectingthefirstandsec- ‘on;butthothirdisveryequivocal,andallogether false,inthesensoinwhichitfataken,—Withoutmeaning, obaythatthe forcewhichchange thestateofbodiesproceedfromsomespirit,Ireadily‘agreethattheforcebywhichthesateofeverybody ischangedsubsistsinbody,butitbeingalwaysun- derstood that itsubsists inanother body, and neverinthatwhichundergoesthechangeofsate;which vail ity,thatofpersevering fnvthosamesate.Ta0faihen, anfvenefrees subsist’ inbodies, itought iobesaid that these bodies, aslongastheyhavecertainconnexions with cachother,maybecapable ofsupplying forcesby which thestate ofanother body ischanged. Itfo lows, that thefourth proposition must beabsolutely faleo; and the result, from allthat went before,‘athethatveryDyinendowedwiththepower ‘fremaining inthesame state, which isdirectly theepponiteoftheconclusionwhichthesepilsophere ‘AndImusthereremark,thatitisratherabsurd fogivethenameofforefothatqualityofbodies ssn nonoovweer,wichaysnaittywoe DZceermandbythettmforceeverythingTost‘capableofchangingthestateofbodies,thequalitysreeSentee enericPoneypmeeat e Seeccc,cengeriaete ieeeitcoinaorneace PLertpoyiogBe reiseSSeeeerence se roehBitloeyhlatonyomeor TintBtesclementOfmatter,ormondeifsuch eeieFescreeee ity,th same Sasorigolitofpornoteoe <ertbesePhllawophers aitemptedtoreducetheel congLaonomereehede Siena earices Stenis nl speed BendSevee state;for,whileIamwriting, mysoulcontinually‘Bependentirely widTtnthovougs FerreeerrelerchangesSerer nore‘akepiaceinbodknazothofectafanSrancous dffle,thinnedaienenbetmannte analhaina,tateApaeanp steadyaaolyofcowreya willbeentirely convinced ofthefalsehood oftheibetycomicaltuealote‘piriisonlyamodification ofmatter,‘Thesegen. enhavenoknowledge oftherealnatureof bodies. | (omsoot AND NATURE OF FoWEns. 289 | LETTER LXXVIL OriginandNatureofPowers. Iisundoubtedly very surprising, that ifevebodyhasanaturaldisposition topreserveitselfit thesansatandeventooppo allchang, all the bodies inthe universe shoud neveribelay be continually changing their state. We areweil as fured, that this Change canbeproduced only bya Kerstotrenen! inthebodywhinestainchange‘here;thenawelookforfhosepomerewhich produce theincessant changes that takeplace inallTrebodiesoftheuniverse;andwhichare,neverthe-Jas foreig tobody" ‘Mastwethensuppose, besides theseexisting bodies, particular beings which contain those powetre!onvarethepowersthemeelves particularaub-tancestxstingintheworld!Weknowbutoftwo Kindeofbeingsinittheonewhichcompretends allbodies abd theother allatllectual beings, namely, theopts adsouls ofmen, and those ofanimale, Must weestablish, then, inthe worl, besides bodyAdopiitayathirdspeciesofbeings,underthename {powerorforce!oraretheyapiwhchaces. Stalchangethesateofbolita Bothoftheselabourundertoomanyditeatiostobehasty stoped Though cannot bedenedthatheaoeoteanofBeansavethepower Producingenangesintheirbodies,mere;how rer,aboundtomaintainthattemotionofaballon Soluteiatretardedandcetore!bree rt;thatgravitywan Tepidcone Daal preseitewetie:downwardandtantoo heavenlybodies,whichintheirmotion,changeboth —_ a200sawnimnaresorrere.direction andvelocity, weresubjected totheactionrennet teen Serenalabs hear bodies aspirit,orangel,whodirected itsSonningithwy rapingSn pharenirlseg ‘weexceptanimated bodies,thatis,thoseofmen.piciiiecraie dacemntetcabat ieevareeerac Begee a,aa thangetestateotbolegexistsparsely.endoxee iaeleeeneteratkeeiakeneogtepratoeee a alaecatiaetds Sataeae ces aearete hearthattheoriginofforcehas,inallages,beena‘stumbling-block tophilosophers. ‘Theyhave‘allSREY SoStTertegmeeea Sepeioe beepeaTae einesibisSatoeine feversataeared aee epee md rei ate say.then,thatbowevercrangeit cnazn alanyroemyspe, eeature2GannainettensSarpeegheeeeee others.‘Idonotsaythatabodyever ite. ererycataceeSerese {ehinebottomoftismysteryreepectingTheorgan Erbereatertte ‘aifnoothersexisted, ‘onioisANDXATUREoFrowsns,261 LetthebodyA,Fig.92,beatreat,andletthe totbhaverectedSoloninthedirectionBA, Fig. 20. withacertainvelocity. Thisbeinglaiddown,theSayAepuedocontinayeatetand thebody'stocontinuetamotionslongthesrkght line BA,alwaye with thesame vlocty,andboth toy BillalengthtencometotouchthebodyA. villalengththencome‘WaliwiibetheoonoquncelAslong tatedA remains atrest, the body Bcould not continue itsTottonwithout passing through thebodyA,thats ‘rithoutpenetrating ititisimpossible, then,that Tachbodyshouldpreserveitselfnitsstate,orithout fheone'spenetratingtheother.Butthispenetra: ton iaimpouaibi :impenctrablity being 8property common albodiesTEbeingimpos,then,thatboththeoneandthoothershouldpreacrveisstate,thebodyAmustBeolutely bognfomove,tomakewayforthebody Bythat Xmay continue’ itsmotion, of,that te bodyB,havingcomeclosetothebodyA,musthaveiation dentro: onthewateoflhabo thinned,enmcaxisnecensary mins ondfton tocontinue afterward eackinBisproper inte, without motual penetration. bothmutsectlyundergo¢changeofthir muaiy za thelr fiat,andtheenuveo¢thnchangeiffyexists inthe" impenctrabilty of‘thebodiesthemeclvos; 102 vumowtsoFTHsinceeverycausecapableofchangingthestateof bodies isdenominated form,itiethea,ofneces- Bity, theimpenetrabiity ofthe bodies themselves hlproacentheforcebywhichthiechangei tected,infact, asimpenetrability implies theimpossibil- . itythat bodies should mutually penetrate, each of them opposes itselftoullpenetfation, eveninthe minutes parts; and{0oppose itself topenetration Grnothing else bat toexert the force necessary to Prevent it.Asoften, then, antwo ormore bodies Eannot preserve themselves intheir state without ‘mutual penetration, their impenetrablity always ex- feria the force necessary10changeitasfaranis equitopreveat theaightet degree ofpone: tion, thatec'ofytaoftheforceswhienarocontinually originof which arechangingtheirstateinthisworld;andthisfetheioeolinoftherelmyerwhchhnperlexed philosophers sogrievously,TtNovember, 170, LETTER LXXVINL. Thesame Subject. ofthelast pose Principleoftheleastposible Youhavenowmadeveryconsiderable progress intheKnowledge ofnature, rom the explanation oftherealoriginofthepowerscapebleof thefaeofouion;anyoutreatpreentinaom. iketocorpcaywhytonofi fworldaresubjecttoaninceesan ate, Tomresttomotion,orfrommotiontoet. First,wearecertainthattheworldiafliedwith matter”“Herebelow,itiaevidentthatthespece | URAST POSSIBLE ACTION. 263 which thegrossbodiessensibletofeel-Iiasisoccupiedbythuyandthatwhenwemake a'vacuum inany’ space the ether” instantly sac- coeds, and itlikewise fills thespace inwhich theBearebiosmove,ANspacebeingthusfal itisimpossible thatabodyinmotion con. tinue ita single instant without meeting others,throughwhichitmustpassiftheywerenotimpene-teal “Andawthispenetrability ofbodies ex:eresawaysanduniversally forcewhichprevents allpenetration, itisnot atallsurprising, then,thatetloberverptalchangesinthestatof ie,thougheveryonehasatendencytopreservefaeinthesameslate. vie1theycoupenetrate eachother feey,nothinginitestate;butBeingTmpenetraNe theremack thence necessarily result force sufficient toprovent allpenetration;andnomoreresultsthanwhatis preciselyneedful. ‘While they carrcontinue inthesame state, with outanyinjury toimpenetrability, they then exert noforce, andbodies remain intheir state; itisonly {oprevent penetration thatimpenetrability becomes| active, and suppliesaforcesufficienttoopposeit. |When, therefore,asmallforceulicestoprevent penetration, impenetrability exerts. that and no faorebatwhenreat foreisnecessary forthisoar‘impenetrabiityiseverinaconditiontoSupply it. i, thoughimpenetrability supplies these pow.reiisimpale saytaitendowed tha Seterminate force; itiratherinconditiontosup- plyallkindsofforce,greatorsmal,accordingto Gircumetances; itiseven aninexhaustible source fofthem. Aslong asbodies areendowed with im- penetrability, thisisasource which cannot bedriedEp;thisforceabsolutelymustbeexerted,orbodies‘lustmutuallypenetrato, whichiscontrarytonature, _— 9040s PRINCIPLE OF THE LEAST ACTION. tienaieemmaatoe body’itresultsalwaysfromthatofallbodiesatSete tears cian tan ofFeinmonkiyriameat Eerimemejarine iin We heTeerots maeneyce cmiy eb eetsistery accaSy Gra eeeSoya gente sosere ane ste rewireeaences iyrenner metaenon mea tie i oes tnt ie tpn acksimmonsterraouelac Eibsh oe ovr, ce Biotin egwmame tron rb teacee arse fonrsee iescaecng eines mestbecov, etnwe mee rrentiepetran btwheniheobangepo. nthesaeafSenietforefet phaoeren re ia a tefot is le renting theper iico Panefnoem prodaestatithechangeoflatewhicItope- tesyt ceeportional; and,‘consequently, whentwoormore r - srncres oF rowsns, 08 Coatinginotatewhospenetretngthelor, $'tmotolactionmuttakepace,whichialwaystbo Smallesttatwanespabloofpreventingpenetration, "Youwilhodhere,thereto,beyortalexpecta: tion, thefoundation oftheaystem ofthelateMr|deMaxperttysomucheredupbysme,and90e-featSacked wer." spots nytaof | the feast possibs seton; bywhich hemetns thatialtheangeswhicapyartocave thich produces them isthe Wess at cabe, er ener whchareenergie a thisprincipletoyoo,iinevidenttatiis fortefotdd'in heveynaarofay,and fat those who deny are/much inthe fone,thoughstilesethatowswhowouldfurnfansFiditle." Youwilairesdy, prtaps have remarked,thatcenalnpeonyomeattne. a oupertes te.everyopportanity of laughingthepilfebpreaclell theholecontinveddowstothecenteoftheearth;atfortunately, tot suers nothing bythelr ples oy, Newent, 700. LETTERLXXIK. OntheQuestion,ArethereanyotherSpeciesofPowers? ‘Taxoriginofpowers,foundedontheimmpenetra- |allteiiveaeendearing pplininby oomeansinconsistent wteftnocewhomistathatthesoulsofenand thoseofBunfavtepoweroftngooUe odie‘Tereinothingfohindertheexistenceof twoKindsofpower,witchproduce‘llthechanges |tatfateplateinheworldheonecrgrtay ‘chdirestorigiGomtheimpenetrabuity le Hae 206 ‘SPECIES OFFowERS. bodies;andtheother spit‘whichthesouls of» seistePathpephg eared other,thatitisnotpermitted, inphilosophy, tocone, sat= Be etn gener brat oanseieymamasregiiciices encesSeiteiuicamoneicene cece iag etSetraeee heSees lg i panty elie pr ee hereTEESE,etn,ofteoo8 cabaret mired oe pallor prety‘therulesofarationalphilosophy, tointroduce anew™ofpowers beforetheirexistenceisincontest- & seieeimrentrina eee icta © SeLeemre ¢ ena ese weer |scsemeter wheurounsbomfat‘thisime|eatin Lieieteashat reali ae eetogive ‘tothesepowers whichimpelbodiesto- Egeackgeoctenaes Brice FeaeMagKayTnfac,theeubtilemattermgwallhavea.eia ody eetaepibraetr meneame ieraceEresTaeagcnarrwich teh Lt oan a rk arnoms or rowsns, 267 Biatespacewasnotfilledwithasubtlematter,the elyofatracion mightvery well beedmitd, ‘8nosuch case exists, wehave consequently ‘reason todoubt, nay, even toreject it.Weknow, then, "but oftwo source ofall thepowers which producethesechanges, theimpenetrahility ofbody, [iethectionofspit‘aednciplenoflfrejectikewiothilaand mini tnprymae ubecan [Remowhentsalge,Oat,necrdingott, ‘Godhimeel,whospnt,could‘nothavethe jpowerofactinguponbods,whicheavoursstrotfath.ayareccnaretueePe feeblereply,thatitisbyinfinityGodisabletoact felephtonGdatat |sirt'suponabody,theimpotence necomiy |recollaon God himeelf’ And who can deny that‘oureoulseteuponourbody’Iumtoauchadegree masterofmymembers,thatIeanputtheminaction ‘asplease. ‘The same thing may beaffirmed like-‘Wiseofthebrutecreation;andas,accordingtothetystemof Descarer,atwhichwehavegoodreason{2smile, beasts are mere machines, without anyfeoling,likeawatch,antheWolffanswouldhaveitment00aremerely machines. . "Those some philosophers, intheirspeculations, go likewiseoofara1denythefstspecies ofpow. rs,ofwhichtheyknownothing. "Fornotbeing tbltocomprehendhowonebodyactauponanother, ‘heyboldlydenyitsaction;andmaintainthatallthe changes which befall abody areproduced byits ‘own powers. "Teyareihephilosophers whomIformerly men- tioned, asdenying thefret principle ofmechanics,respectingthepreservation ofthesamestate,which itulicieny toouvert thtswholesytem." The fervor into which they have fallen, as Thavealreadyremarked, arisesfromtheirreasoninginconelusively 268 srRcinsOFTOWERS, sopestingthe whichbodiesprseatto SPTnefcondtedprocptataly,fromoberring ttinoatalbodiescontinallychangingtheirwate, artheycontainedintenecives tepowersbYitiyneal exertthomelvn tocnaweretheyaughtfohavedrawntheready foeoochesanePeisthuethat,byconsidering objectsinasper.|foilmanner,wetaryintothegrosesterrorsTSvealrendypuntdOutthedefectsofthisreason"igsbetontfallenintovortheybaveabandoned{Bfwavesfothetostabwirdens,”‘Theyfeet secrettheseinternalpowerstothepeima'yele: ‘meatsofmater,which, them,arecon: nualefbrtato’changstirsafe,nd.Consloded fromithatllbeehtngestowhicheveryelement {inbsotedtreproducedbyitsownpower,ndtattwoelements, orsimplebeings,cannot‘actupon eachother. Thisbeinglaiddown,itwasnecessarySidestnlabg,oalwero ‘etinguponbody,boweree, aeBoing;Endthetanbotieerecompenedof Doings,theyworeunderthenecessityof tlvoatbodicecouldactuponeachotter. ‘Itwasinvaintoobjecttothemthecaseofbodiessiicringins oanonateranibe SrtbeivatewhichresultsfromjeObetinaely froponecsed infavourofthehdloftheire. Eeethyscaredtosadntheychee Fatenineveryody,tomieae ture,produces thechange befallsit,andthat theslatebsnothingfodowihthtiefo’thecausaftyandtheyGoofineemphat thocaueeofity pr aesablontyofapilowoplybofarbeyoodtheSpittal igeFonreow,int ion#0estimateWtabcondingtoirealime ‘95thNovember,1760. |(OFTHENATUREOFSPIRITS.200 LETTER LXXX. OftheNature ofSpirits. Iriarren myself thatyouarenowconvinced ofthesolidityofthereasoningsonwhichThave.ex-tabled theknowledge ofdio, andthatoffhe powerswhich change thestateofthem.Thewhole JPtounded onexperiments themoat decisive,andon esciplen dictated byrevon, Theysana Ebwurdity,noraretheycontradicted byotherprin- iplesequallycerin.”tienotlongsaceanyreue-fecalprogres wasmadeinenearchen ofthieKind.SuchstrangeideanwereformerlyentertainedTeapecting the ‘natureofbodies,thatllkindsof powers were ascribed tothem, ofwhich some most Receesarly destroy theothers,Certainplonophershareevengone0fara0 imaginethatmatterselfmightbeendowed‘withthefacultyofthought.Thesegentlemen, knownbbythename ofmaterialists, maintain that oursouls,andallspiritsin.generaarematerial;orrather,theydenytheexistence.ofsoulsandspirits.But‘whignoncewehavegotintotherightroadtotheoowindgofbodienrinerbrioofwhich{halqaltybywhichtheyateeabjctedtopowess tapalle of changingialtho of leofcl itthosephantoms ofpow- SebowhichTafedvanoh eweandnotingop pear amore stwurdity than todim thatFratericeptofthought.‘Toain10Jods {0emon, posses mental felngtorelet rategualites incompatible withthenatureof Todies;andbeingsinvestedwiththommunbeof@ Giferentnature.“Sucharesoulsandspirte;and He whopomousetheaieinthehighestdo * +. 370 (OFTHENATURE OFS7mETS, .‘Therai,thn,ainfinitediferencebetweenbodysantopt”Exteosiontere,andpenetrabilityeal lhexcode afonghemae heproper.Teoriiy,bateineedwiththeent fefectiog,willing&otdneraigiatroteet tne obit preferay toanother.‘There twhere folie ation uraynorinert Tees material gales are faintly remove {om rileasked,Whatisspirit!1acknowledge myiguortacein'yopectoflaaroplyThatee Stooteuwhat"aaweknownothingofthe SatureofepisaiiDot,theJeonomrtadaCantthisworldcon. -: ormete, Plandbagstumaiotalofil,hienroof ‘anature entirely different,astheymanifest them. tatesfonyroernnwichvenorelationfo eachother. Theostwospeciesofbeingsare,never:{Beesoats atedandupnheaon Eilat dhofintligestbingyaload eaetatoprtscovathepeincipl| eieeorth aTeinae‘abetted itiaerlytoservethem.YorUseensonth hatthesoulofaninalsrei'sunionsointimate TiBhMeehodio.Notonlydothesoulsperceire Aivgiteforgot sceaanbotycede| Tiyreastoue ancctveintaesbeorttheaoeof ‘theworld. | aaiyi,nadverllostbe.renienpattyof is,andeverwllbo,thea GedivineOnmipotence“amysierywhielweall ‘overbesasoaniad.Weazeperfectlyseala ‘thatthehumansoulcannotact ionall {WHIONBETWEENTHESOULANDODT.~#72thepartsofthebody;assoonascertainnerveig fteannolongerlos‘aynd:fomwhich {ayboconctaelttthsolhaspowerolyover fhe’extrmionofthenerves,whichalterminate fteinsportionohrinhepacofwhen {hemostalIAlanatomistleunableexactlytoa0. ign.Tothis,hen,thopowerofthesoultare-siicied.ButthatofGodbeingunlimited,extendstothewhole universe and exetsitelf bymeans |hichfrexceedourcomprehension |abeNewer, LETTERLXXxx1. OftheUnionbetweentheSulendtheBoy, ‘Asspiritandbodiesarebeingsormbatance,of saiatutotallyGeren,thewordcontain,then,fokindsofsubstances; theonepinta,andtheercrpelormater"heetaanwhieh tubsltsbetweenthemmerits‘averyperticulra |nisnonofsoulandbody,ineveryanimal, anionofiaie unosrootedphenomenon,”Iireliedtg {hingeineovetbatthesulfeleorperesiven,al theSang ichteflieby,byenwofte tunsee,whic,asyouknowperfeclywelsreive ISnolvsngRearingeelingating, sdtouching,Bythshn,tesoultskog Sunbodybakextof.Totehingandtangertiolhoeobjectonlywhieharenmedsnine “=emeling,objectsata Ehteceybearagoatstodanbentactsloarotoundsighprocareeforustheknowiedgeof CSE pinamre is inwhee heobjectakoapresiomotaneoat u 2 ‘UNION BETWEEN ‘senses ;butstillthisisnoteufficient—it is {har'thorganofsuchtenseshouldbeperiecly tomasGeartsboningftetbe SermgeYouilecoleatoerae, theoljeciamostbepainteddstinetyinthebottomoteeye,ontheredna;bataltisrepresentationfnot‘theobjectofthesoul;onemaybeblind,ThoughitisperfecdywellGefised."Therenain¢ ontetture Ofnerves te eootiuation ‘ofwhich {Srrptedbyanyinjurydovetotisnerve,caledtho :ferropedbyan oetotisnerve,eveYoerewilbonosghhoweverperfoct ‘Serepresentation onthereliamaybe enthesumewithexpecfoteoersons,all oferatbyegopveed envoythehnpresetoamasonthesegsa {2thseneston,uptoisSitorigintnthebeta, ‘Therethen,iathbraincertainplacewhersTessteriheoes heeitcientinpresnoasmaepon ‘™Fyomtheseimpressions, thesouldezivesalltheXnowiedge thasofthingsootofHeel,tenesit {Reonhesandyhiconanore te,reflection, andeve ieclrry ptiinoweige!mechotewrk ofthesol,fnwhichthebodyhannoshare,"But iheieen comes6Iromihbene ‘Soroetoporeortofnwhapuesinfat 2otfol,whapases Tene’"Tieactlydenominated Jesag’ot “Tusfculyia or sonstandthecou,pearlypoasve,soéenoting, trhlhbodyprecenstoteevee merowsons ™* utiposseneesinistumanactivfaculty,by smoaueofwhichthasthepoweroffoeuctey”12 pty,andofproducingmotionsinitapleawaresia ‘SieConsistspoweroverthobody.”ThusI'am smesou.AnD2oDr. mm Abletomoemyhandsandmyfeetbyanactof PilsankWhatmotionsaremyagersmakingoy* Torte thin lester! Mysoul, however, cannot act ime ontyonofnyfogere’ nie fo aeaglonettmoonyiteteenary thatser Fimoetles shouldbeputinactionsanteacion quia exert tel bytenn ofeves terminating posewillwishtynerYomove?wiltolonger ‘rillwiahtytnger10overawilllokger BeyBereroySuliepowerey foulextendsonlyfoxsmallportion ‘hersaltebetwee niessenetion inikewiss Teatrcted tothisplac ofthe brain."Theeal,thenunitedonlywihtheseextremikonofthonerven,onwhichithasnotonlytheperroatinstlnrofwiecnom Er"a'smirroreverythingthttakesa2 Sionontheorgunnofitbody,"What,wonderful dros, tobeable toconciie, fom the aightChangeswhichtakeplaceinthe’extremityoftheSereratwileScioshutofthe ve "Rtre, forexample, producesontheretina, itraeaninathicksporesmia bathow feeble tumt theimpression bewhich the Berve eis fomlt tspreston, baw‘ver,coninneslongthenervesuptotheirorigin,SwickexetesfntheoolthodenOfthattee,Trward, thelightest impressions which thesoul maker onfheentoation ofthonervor eristantly Commonicated fothemacles, which, putin tet, ‘hemenber which iwile 10"wove, exaclytochoyitontersdrawingfgfoefteureettThelwontsofheCreatorinatesurpenthepesof te =tectorofhumansi ee ‘3dDecener, 700. cid ‘UNIONBETWEEN : LETTER LXXXtL DigsSptlativeohSujet Inonder welucidate the two union ofsaulanfsefouteirfalnionofa sebtotemaycompenaoeSa ges Soten tneknowicage af .SieSpugoteroomSowele, feoofneeieecarapr Rebeka ae epeeovalSetnlealte Serer heneeeFoe eertedeoat oom,hericommsheean fhErie ec entedtheyare,however,verypropertosupplythesoalThenctionbywhichthesoul.operatingontheexten hesanealoprete Biteatspayerosperpenteepion easeasaoeParrTES EESpemenThecomproonhowe7 Fe oa er Fanaaaoraarti reget0foe ‘ing,asthemanplacedinthedarkroom;itismuchtng,gmanaceaooach‘aresensations highly agreeabletoit,andothers deamonaSonpeee fromabadtootht ‘This,however,isnomorethan SeeereMetainPcsnaintar,walyethae esaoe THE SOUL AND BODY. Pt) Inwhateverlightweconsiderthestrictunionofsoul andbody, which constitutes theessence of living man, imust ever remain aninexplicable mystery; snd inallages philosophers have taken fruitless paing, inthehope ofarriving atasatisfac. tory solution.” Various systems have been devised fortis parose,"Thedretis,thatbywhicharealinfuenceisestablished ofbodyonsoul,andofsoulonbody;90thatthebody,bymeansofthesenses,supethewithile reeptions ofextern 3 {ntcatthesou,byatingimmediatly onfhe nervesintheirorigin,excites inthebodythemo- tionofitsmembers: though itis atthesame time acknowledged that themanner ofthis mutual in- fiuence isabsolutely unknown tous. We must uadoubicdly haverecouretotheomnipotence of ‘God,whofasgiventoeverysoulapowerovertheportion ofmatter containing theextremities ofthe Rerves ofthebody, sothat thepower ofevery soul isrestrictedto«smallpartofthebody,whereasthe powerofGodextendstoallthebodiesoftheuni- Yerse.Thissystemseemsthemoetconformableto {ruth,thoughweareveryfarfrompretending to havo'aparticularknowledgeofit. ‘Thebthertwoaystomearetheinventionofphilosopters,whoboldydenytheposftyofFellntdence ofspiritupon, bodies;though theyareunderthenecessityofallowingit10theSupremeBoing.|Accordingtothem,thebodycannotsupply thesoulwiththefrstideasofexternalthings,Bor thesoulproduceanymotioninthebody.‘Oneofthanetwosystemswastheventionof Descartes; itgoesbythenameofthesystemofce- ‘avionalcouses.Accordingtthisphilosopher,when theorgansofsenseareexcitedbyexteriorbodies,(Godin imprentsonthesoulttheame instant,theideasofthesebodies;andwhenthesoulwillsthatanymemberofthisbodyshold cowre‘move,stillitisGodwheimmediately on cheswameenodyabouveemachineofsuchsdmurablecoorSeesee , tingly,soonlostmuchofitsSeeeelFoltveno.doubtentlyheardmentedis contigtothi fpre-established hare Seeeee rmanivsluatenyoomabtanes Faas s ieeeeste foe eee Stier oetriosthebody'shavingtheeatheretntetat?SeemakesSepa nee Sarees Soe See ea Bae eee‘hand,LeidnitesaysthatGod,havingforeseen my «tatinvitesafteproperorgesaakon maySeehand necessarily iceafthe‘sarooinstant,and,inlikemanner, thatallthemotions ofthemem-See ireeroeStree pena iraae‘withthedeterminations ofthesoul, Sian vertu oyvur-serasiinnzD manwont, 277 LETTER LXXxm. Esamintion ftheSystemofprecstaiched Harmony.“inOSecbontoe ‘Tweaswasatimewhenthesystemofpre-etab- UshodharmonyhadacquiredsuchahighfeputationeralGry,atarcalinGntion Srantoincorthefnputaionofignorance,erbigoty.‘hettapporrs ofthisnyesi, By roa oft theomnipotenesandomniscienesofthe Supremefcingweresetinthetclaretlight,and {ht was ingocsile forany onewho beloved {ess exalted perfection ofGoa tocnertins doubt oftheth ofths subline ayetem, Infact aythey, wescethat poor pitiful mortalsareca conrucingmachinesoinetonly fsto hiltho vulgar spectator with antonishment” {halGodyhavingKnownfromalleternityatatmy vingkoawn from alterfoulwoul!wisanddesireateverynyeant,shoudiveBeenaletoconstructochaoachne,whic,Mtovery Tostant, should produce motions conform: thisothedeermmationy ofmyou!” Nowyha Tmnchine isprecielymybody,whichiunitedforoy foulonlybythsharmony,fothatiftheorgani fonoftybotywerederangedaechSegre0 tobenoDngerinharmonysathmysoul,tnebody ‘wouldnomarebelongtomethanthebodyofthiTeceos intees6Aaaihecme oraderangement ofmybody,Godshoud Ghatgf'sMinoceroe00thtiamotionsworeia tachhermony withthedeterminations ofmysoul fatraiseitspawatthemoment{willedthis Bodywoldtheneming,nlwuldaang 20aSayprestosowbangswiht 78 svermxoFhavingundergoneiteef,onthataccountanychange"Md.Lebudshimeelfbascomparedthesoulandthebody 10two clocks, which continually indicatethesamehour.Aclownwhoshouldseethisbeau {ifal harmony ofthese two clocks would undoubt-celyconclude thattheyacteduponeachotherbut‘hewouldbeunderamistake,ortheoneperforms{ismotions independentlyoftheother.Thesoul andthebodyarelikewisetwomachinestotallyin- Aependenttheonebeingepiriul,the oxhermate- rial;buttheiroperationsarealwaysinaharmony >completo,thaweareinducedtobelievethembelongtoexchother,andthattheonehasarealin-fluence upontheaber,whichis,however, amereTnordertoformajadgmentofthisaystem,Ire-‘mark,first,Thatitcannotbedeniedtobepossible{forGodtocreateamachinewhichahouldbealwaysJnharmonywiththeoperationsofmysoulbutt o'methatmybodybelongs10mebyother Tigitsthenochaharmony,howeverbeautifalit maybe:andIbelieveyouwillnot.bedisposed TBamtilytoadoptasystemwhichisfoundedonthisiniplealone,thalnospiritanactuponabody: ndthat,reciprocally, abodycannotactupon,oF senplyideas16spit‘Thisprincipeis,besideectinginletpavingboenmpleeTespocting simple bein ‘completely re-REE eeteeben rheeeofactinguponbodiesitentsbeotelyinponebie thatapint,suchasthehumansoul,shouldbeablelikewiseto’actuponabody.Accordingly, wedo fotpretendfoaaytatoursulatauponallbodies, ‘at-only upon asmall particle ofmatter, with re-‘ecttowhichithasrecoivedthepowerofGodhim‘efthoughtoexerciseitinamannerwhichweare‘Utterlyunabletocomprehend. ; rasieranuiosD wanwonr. . 279 Further, the system ofpre-established harmony_aboursunderothergreatdifiaties. Accordingithepuldees Krowedgyfromtoewithoutanycontributiononthepartof Theboyandthesenses.‘Thos,whenIeadintheBz, tthepopeisdouandcametotheedge ofthepope's death thegazette andmy reading have nothing todowith thecommunication ofthis Knowledge, asthee circumstances respect ‘uyaybodyattmysense, whichhavenoaner ofconnexion with mysoul. But, conformably {othis aystem, myaoul derives, athesame time, from itsown proper fund theideaa which ithas of this same pope, itconcludes hemust abyoltely bedead,andthisknowledge comestoitwiththeeating ofthegaat, ohabimagine thoread ingofteguzetefurniahed mowith thisknowledge, though Tallyderived fomtheproper fundof"Dtthieaiprtctlyaban.owwasit potnible forme20 boldly toassert thatthe pope ‘oun necessarilyhavediedatthemomentmentioned iEtheaa, adthatonyfomfhenenwhich had ofthe pope's condition and health, though perhaps Iksew nothing about him, while 1am ,ay beter‘aunt withay tution, without knowing, however, whit shall befall meto: morrow. | Minke manner, when you domethehonourto readtheseletieresand deretheknowledge ofome {rathfromthem,itsyoursoulwhichextracts that EruthfromiGrape find,without mycon.ftibuuingatallfotbymyletters.”Thereadingof them serves onlytomaintaintheharmonywhichthe {retormeantfoenabetweentheoanthe Eisonlyaformality ersupertnous Iwlyrespecttothenowledge teiTahalnever: Theless contin totender you myinstructions. th December, 1700 0 sveTauoF ervenuxxxry,sowOi.rpautorspinaboe dapmiaoreie aterdareiy,nceeneteft eoeremeretr aerences ofa Some eresereneayee ‘saryofthemachine ofhisbody,asthemotion ofSica heew tg ty akrrcoeeYe SeeSareea ome Pattie atefecesae hynenhoelceatceespecttothethief,whomitwouldbeabsurdto meee ae SSheawaera hata rea aagi elyogo Tigre!elosete, courthavingst tohimthat; lingtoMr.Seayngersint A, one ireenomak Sececoredmeee seenea, econae Seeatecilarene rae Seyesemrenetag aaafingers etfePbetieeneh meen pred *il ynthistookrefatMa;,whereFelcoerro a rissrnssumnrs mssort. 381 Butthoparnansofthiseystemhaveal smantainodfatthepre-stablishod harmonybyzo TeunencroachedSehumantbrTeyheeTeeter ateneaeeearttyees oftheorizationofthebody,andthat,in‘this. PepeHererst‘teensynimt eerschBaatheneildetermin cine.tatinecanybeanon oPpmickmentthough‘thecorpora‘ctionwas feennryrniheinaiofanactionconse Toveatormotonsoffebethasae Detar oe eee Strip fos, ‘Latur socava sy lho esolOteettetcrane emt roaberyGadbalfresen htnin aw feoitndoralchset Bet 'erodone;precod fthesamo tse the mo: fheSune lrCommnn otsit "cidentUhepia'toclf hegeceoe ofthenj of‘the.body,utthattheineteton fe iw aywih tStatog atacount os ‘clade‘s'Notithtanding thireasoningth nat ithstnding thisreasoning,thsopptre thosystem ofpre-established harmonywilalways findthemsetvesergmichembaranedtoaaa Jthelibertyofthedetermination ofthesoul.For,selemahsselasSlstaga’hie Meagh os mabre total dideent oon aosBHSeremtnttceprokaced tars ‘occasionedbythosewhichprecede,andthese byothers anteriortothem,and000,#0atKey ,— Bhageeec ether aoneem astkemations Srmarhnes nfo eyGey ten aotaye on arene andl onis mepoeatoes ot Seok nsscecohtecouorolya etefoilrecollectthat,acortngtothissytem,thesoulderivesooneeafromthebody,not 183 uimxryoFsrmurs, beinginanyrealconnexionwithit;betallfromite rnproperfan.Presenteesowfomthous ‘hietproceded, andare&neceeearyconsequences‘ofthea;oothathesoulinotinglegethanieatergowndete,whichrpratesaeoltonmae ShickaethereforeaxGiteundofapowerand ‘Sonsequently alltactionsarefoundedon ‘entstate—tbat ontheim (receding)aad Soontrewneceworyeectoftefestaioit ichKwacrete,overwhichicartanlycould Trvenopowerandofsansequencecouldnoteree, IndeprivingmenoftheirAberty,alltheractionsbocomenecessary,andcannolongerboconsidered"*So'ooeSftnexepilosophers hashithertobeen jo0000sblstoemovetheoduties;tndthetnlvers: rieshavearighttoobjecttothem,thatthisopinion issubversive ofallmorality, andmakeseverycrime IPunoasedythegroseetimpity.Wemosttot Emaevnere at consequences,ywverynaturallyfrom fhetrfrncpins"fhearcooferyw«eam lingSlockInpdosophyanditisextremelyaii caisaercloarofthedangerswhichprestonal 18thDecember,1700. LETTERLXXXV. OftheLibertyofSpirits;ond«ReplytoObjectionsgoinLiberty. Toificultiesonthesubjectofliberty, reson sterofbet, ‘Testofdiatingunttngwithsuticietetenoabe tweenthenatureofspiritandthatofbody.TheWolffian philosophers evengosofarastoputspirits sununrrorermurrs, aa endtheelementsof‘onthesameting,and (Gretetouthoonodostheothrthe,makeof ‘monads,thenatureofwhich,according tothem,con-tiesikthepowerofchaigingthettat"fom fehonceremltithechangesfabodice,antalUs‘prinadelousofep ince,then,itisaystom,iectualstateof bodio ta ofopts tlre doeriaaton fatSeiimatelyprecedente thestone‘Melprecedingsat,itievidenttatiportyim inesitinevieotthatortf'no tmoreataurbuteofspnthantieofbayAs TDeboly,iisimposoble toconeive. inTeast fhado’kin foreryaloesupe itepowerofcommitiogofstagoofmae pondinganactionandistodirecoppoeteto EEpeesiby."WoutHot?thom,be Ficulgaltoexpectthatawatchshouldpintto Tayotherhourthanwutioctaldoes?endte ihofpingomitaccount”Woud ‘otbosbeerdtoByintopassionatapuppet,be- fauseafterseveraltheegestures,ithedTeedte‘Ailthechangeswhichtakeplaceinbodies,and ‘waiibechangeswhichtkeplaceinbodies,ithe‘acltohesaaoffena otoo,arethon ence theRRS phatsdastnoea tolageatodiecantakepcebet Esalyouchardotakplace:whatreapoctebody,{SerleisuablocStonerpasenoranslowerstngeaioullyspiceofweckesieney constructed, the commendation whichwebestow honiroverstotheatint;thomachineectusDDlstereeinwhatpswoe;theari,to,ieoweresponsibleforthedefectsofaclumsyandawkward Imachine, themachine itselfisentinnocent. leytrosurlyinnopectrenpounle; no‘wall,nopunishment canpossiblyatachtothem; a “me oom‘ellthechangesandmotionsproduced inthemaretecmerssotmotossreete garecommen teeeafeigeetappamiatcipaie I_Sepa ears Seconecaeroemriet Siena pornofnttemckdereieTentaeRepteatinPopefeatorersEeEraiteDatosTosSloeSegtered easPelee Beret cnimeotbee,er Scorer Shagen ceofcaay eaeenaeek SEU Taha ye Tyee Bathestofenaeboneneemoeettheoblecuonscommonlymodetohumaaliberty Yeoymala0 arethese)optitineaoremameneveroe.Sarre hae ie alswromein ee Eaigmicctersarane os setetdeTreeoftakehhhecere determinetheactionsofmen,justasthemotion ‘ofaballonthbilanableisdeterminedbythe ry idSecttroweleco teaf .Butitmustbeconsidered thatthemotiveswhich Be mo ace recesreegamewereeyulinrerSEO" mona eat oea,ereem ae repaseet ‘werypowerful motivestoundertake ajourneyto‘Magdoburg—a regardtomypromise—the prospect. umeryoFsemirs. 88 ofenjoyingthefelicityofpayingmyrespectsto‘yourhighness; butIamperfectlysensible,atthe ete; hawanaotfredtotsandtat ‘wasentirelyinmyownpowertotakethatjourney, ‘etolavefomaiedseBerin Butbodyimpaled byanypowernecooanyobeynanditcantbe shiedtattwasaUbetytoobeyorootait ‘Themotivewhichdetermines «spiritto {taresolvesisofanatureholyerentfomcouoFforctactinguponbody.Herethellcit Eivaysvoluntary,attthosoulheepowerover ‘voluntary,andtheweroverit. Onthieifoundedtheinputaliyofheactionsof Aapint,whichmakesifFesponileforthom,and thisthetraefoundation ofrightandwrong.‘Steenspntantiy,thequeron respectingterypeseryndicy ft 1780. .LETTER LXXxvL. ThesameSubjectcontinued., ‘Tae difference whichIhaveJustestablishedbe- tweenthemotioesconformablytowhichspiritsact, andthecausesOFpowerswhichactonbodies,dis:scorerstusthetefoundationofubery. ‘imagine«puppet#0 ‘constructed, wit vwhecle'and springsastobeabletoapproachmy Pocketandtopickoutmywatchwithoutmypor- EcivingitThisaction,beingwneceeary couse: ofthe0maofthemachine,could SECTcoundorolunrotbery,andLshoudrene dormyselfridiculousifTgotintoapassionatit, ‘andineistedonhavingthemachinehanged.Every ‘Onewouldsaythatthepuppetwasinnocent,and 786 LomeeryoFarms. ofcommiting »blamoable action; it soulbe,beside,equallyindifernttothepuppet tobehangedorplacedonathrone.Butiartisthad.contrivedthismachineonpurposeto ochmightsomitetheingzoulyieplayedonthe "ion ectmn{shoulrectormycohigedtobang ‘himtojusticeasathiet._Itfollows,thet,thateven featbegsoraapr,aldthtspritsloare ntbeing,or apiri ‘a6Fesponsiié forthe scions.‘iateverymanexaminehisownactions,ndhewillalwaysfindthathewasnotforeedintothem, thoughhemightbeinducedbymotives.Ithisao tionsarecommendable, heiaperfectly conscious ‘ofmeritingthepraisesbestoweduponhim.How-semanas teeniecannotInthiocao;theeatinenofhisber1sintimatelyconnectedwiththatbert ttheyareinseparable, Ttis enter- tainGhat whoretheibertyoftotter ivcoo- Seroed,batiimposeoertbedeceivedre. ‘one'sOwn. example, on Sarliadseeesath ‘imagineittobearealthie,andthatitlikewisewas trireopectohnownery1Impostor wit 0hisownlibertyitim Bimamtako;annodeemReeee,bets9 {nfact.Itmightlikewisehappenthatthe’clownin ‘question,undecelved astothepuppet,shouldafter- ‘rand considerudoxterousthiefas&machino,des- {tateofallsentimentandofliberty:herehewould, {allintotheoppositeerror;butastohisOwnao- tions hewill neverbemistaken. Ttwoulthereforebendcuoustoaffemthatit mightibleforawatchtoimaginethatits sdararely,atobtnthatnowpais tonnine because itpleasestodo20,butcouldpoint 40anyotherhourifitthoughtproper:thewatch bers or war, a rs pty i ea vo Seueror es are Demeraraten accordir suppoeitspiritorsoul,whichneces- SPM Tice caters TL hoe, ee te onessae Bret pt ware eucam ey ek Habel peondeae eaieeecercaae ivan POL ata alSoae by-and-by laydownmypen,andrisetotakea aayct Si haat SEene eeererat en,andofrisingfowalk;anditwouldbeimpos- Feet tet SEES chteee! hereshe 6i, al eTatieea day, such anaction, itdoes not follow that Ishall RetarareGaiaSenaSeah et Sal ‘Jfpropertogoontowrits,Godforesawthat |Siig ses uncelrariasmatinee ly hotel }tenrhentte Byeseilanaerate Sees Rte eTSeatiasSAU akSSS LY ‘ 18 maryovsrmre, ‘inconformity totheseeffects,whensimplemortals,suchaswear,frequentlyexerciveasimilar Seicnoe"Youcancan‘imaginetoyoun"a wakingcousdeati’ advantage owknow60 Yow fbrcerabewillnotfltoavalhimecltof ‘Your knowledge ofthis, however,hasnoinfluence ‘upontheman;hegoesintoitwiththefalldeter.‘inationofhisownmind,asifyouhadneverspeatfetterSoqontedwithmen axltheidopowtons, ter en, ir itinottobedoubtedthathecouldhaveforesees ‘heiractions,inallsituations. ‘Thepreecienceof Ged,withreapecttothefreactionsofspirits,ia ‘everthelese foundedonanother ‘thatofthechangeswhichmesttakepiaceintheeorpo- Tealworld,whereallisunderthepowerofnecesatty.‘ThiadiatintionshallbetheopbjectofmynextLetier. 90thDecember,1760. LETTERLXXXvuL. InfluenceoftheLibertyofSpiritsuponBrente.Itheworldcontained bodiesonly,andifthechangeswhichtakeplaceinitwere comfepetcnoftheieofmode,coryte thepowerswithwhichtheyactuponeach other,allefentswouldbenecessary,andwoulddepend96fheitarrangementwhichtheCreaioehadoat Tahaoftheodinoftheunvere;sothatthis ntonceeatit‘mapoe- sibleYorothereventsafterwardtotakeplacetusn howewhichhappeniathactualorderofthings ‘Theworld.wouldundoubtedly beinthiscase’ .‘meremachine,similar.toawalch,which,once‘wonndup,afterward producesallthemoticnsbywhichwemasabeetime, sanary orernie | terol«monolokoh« iaetFeeehad ‘virtue ofits.construction, without any fresh appli- ES Een en MeSeLitea Saatni Rep cnet Berm, eto etlatestheairs,orbywindingitup,itisanex- Tofteile latoeee ‘izationofthemachine,nolongerappertainstoit. fatSata aletens |seinSheeSodageraissanity 3 pgaSTAsara neeAmiracle, consequently, isanimmediate effect ocais Semeur hon as, ie aeseharatrratie setasee Fash"eefreon" SaewosBUtaaeatteiadlst in’thateaseitmightbesaid,thatalleventetakePatino annepecenyech guestenghiehteceeoe tears ios et Sey BetteiesBien whttayltataneous "thetpoten peer oe&ttheorganization ofmybodyasthatofhe Setceeay at toaih ol dad Siete ihSoatehyaill ieia yeTtpayTa taymongikopeofeatleweesaut,consequently, sccotdingtothissystem, 200 uunearyoFsrmuire, thomivareiamerelycorporeal,andeventsare= Doceaayeetoftheprinttiveorganizationwitch GodnesYeatsiateuniverse thepowerofprodeeingmolonintherbode, 2powero‘motionintheir whichtherorpesatonlonewouldnothaveprot Soced, the ayeiom ofthe universe isnota mereTonchine,andeventedonotnecessaryfakeplacetaintheprecedingcave. ‘Theuniversewilpresentovenoftwokinds oFinhococe;wAichurecorelorSepeadentence,whicharecorporeal,oron themachine,asthemotionandphenomena ofthe{hoveofwatch,anddpendentirelyontepnt ots onthepam tiveeatalehmeat oftheunrerses ‘TeeSere dependonthesoul,unitedtothebodyofmenend fnlmala,andaresolongernecessary,aathepre- edingbutresultrouheHier,anomtheWi,ofthesespinbeings, ThesefeoKindsofreatditingiahthewsivereefromteremachine,adreetoarkfey more worthyofthe:AlmightyCrestorwhof ie"ThegovernmentoftheasvereewilUkewise vorinpteuswiththemeatsublineseaoftheSovereignwindomsoigoodnessofGod. Tenanorehaery.wickinahr solateyeoveialtopirban8‘ate. noeontheeventsoftheworld,"Youhaveonlytoomsier.the fal covecqucnces ofthose, warm, ‘which sieral from frumen scion determinedby Teir wil ortheir eaprce, ciaWhichtakefac’donotdopedoelyonthewillofmenandanimals,"TheirpowerieveryTite,beingrestrictedtoasmall’portionofthebran,fn'whichallthenerveterminateandthis ‘ctioniaconfined0thecommunication ofantm bremionofacereinmotiononthemeters,Which mayafterward operateonotherbodies,andtheseSUITE Gg en eee evry ih mtr of et en SERS cae hares ie ep tenn See meee wesareryday‘seethebestconcerted projects failing,Rieianmene ee Beles alecearn tater suai mace et els ierecait cara neue tee iret tradi, camace notoae ‘ateuteonhecrestedthisuniverse ‘Thisreflectionplunges'usintoanabyssofwonder 2a ee snobjectworthy ofentering intotheoriginal plan Reese hae Fatal OfBNaptMrtycoon iyen nth ches pins sea a,mocaversaeeres Eeirscama wor a oe 208 ovxvaurs,ducedbynaturalceuses;sucharethephenomens ofthotenvenlyRotieclpes,empet,whirwinds earthquakes, dic.‘Thesearecallednaturalpho-‘Romena,becauseitisunderstood thatneithermen‘oranimalsareactiveintheproduction ofthemn.igreaogaoetomupbyterot,troughtheYiolenceofthewind,wecallitaneturaleffect;but ifitweredonebythestrengthofman,orthepro-oanofanelephant,noSpewoudcallthls inistonordestroyedbythhaiwssy’the 0,OF |Won gateofhiclaywanSatarabaitchemie chiefweredonebytheinvasionofanenemy,we ‘rotolongerdoomincaneof10benaar ‘suchanovilweretobeproducedby0miracle, orbythe.immediate powerofGod,wewouldeaytrovesccanonediyfeaoremalewewealwo, were menorwe thatcae;giveithenameofethernatralof‘suporuatura, Wewouldcharacterizesuchanevent fimplybythenameof‘ction,whichdenotesan decthatimiter satatoysopernatral:‘ tafdopondsontheibertyofaninteligentagen.” "Thus, when Quintus Curtioa givesusadetailof {BintheKnowledgeoftheovebroughtshoutoy tonstheknowledgeoftheeveabout fhevoluntary determinations ofthatReo.Sock ‘anaction always supposes freedom ofresolution in sprit! being: apowerofdetermination which Gependsuponhiswill,andofwhichheismaster. Vtay,ofwhichheismaster;forthereisagreat ‘arielofmotions,the,Productionofwhich,were Wwetodetermine towilthemever#9much,weshouldnot,however,beobeyed,becauseoversuchmovementswehavenopower. Tamnotmasterrendalthemotionsperformed imyownbody;thatofmyheartandofmyBlood SUPERNATURAL AND MORAL. 293 ‘tvnotsubjectto.mypower,ortotheempireofmyRatt weyeeome | RS See BER eur aca Sty Sige mayhoeenoneappaprite temallthenedierent kindsofSel eta ated enna oth ate geen aac Rroiedceecmeteroge oie ferratalnecbaae suice taSaet cpe et SERIE es Pie ae Zoe renee weno ‘thing ofthese, inparticular, unless byoonjecture merely ;andinthiswearefrequently very grosslymistaken.gotalonepossessesthisknowledgeinFromthesebrokindsofeventstherearisesa isben.OFtsBelladable fmiobea example. The strokes impressed onthe balls de~ epaulets Catt BesacancatsSee ‘In general, mostoftheeventswhichtake placeon RES Me ea chee Beit ikEatsae 24 QUESTION RESPECTING taryexertions ofmenorbeasts;butthe isSeeenter:ieae ofimportance toremark, thatGodactsinamannerabtLivesorattiodect optic“Cass Seeatnatoot, formablytowhichallchangesnecessarily takepiace; ‘asbodies aremerely passive beings, which preserve JomotaeponthetbyOlnraeelforseeeee creat foe oFconstraint,bataregovernedofGodbyprecept ‘ithrespecttobodies,thewillofGodisalways meFeather reer aLasaeaten eeogeeNet PoeHnaraadtheheworGeass PeshalTobotasine,eaGentPression, commandment whichmen:10abey;amr eT: 2acemekfstheMeeehecontais aefrere tloubeomy Seercert’deena scratchopaseteeeee Siiterencorf" Tikedoeectnsetapa nagatrien ak Doaneen LETTER LXXXIX. ‘theQuestion tingthebestWorld ieOfheeonstingteiontpor Yorknowwelthatithasbeenmadeaquestion, Setodined.thatthewordpestecdycor‘cannot ‘bedoubted, thattheworld lycorresponds to ‘TREORIGINOFEVIL. 296 theplanwhichGodproposedtohimeelfwhenhe creed ‘hetobodies and material productions, ther ax-satgeenandacreaytatcornyay athavebenbetterPleasetorecalletteeSooderflstrcofheeyandyouwaleeeea sing taitconformation ofa Eisparasperfectlyafaptedofallthendinview,thatofreproveating Cintctyexteriorobject,How ich siren Secnnyioheeyopeoyuia thatstateduringthecoureofawholelie’‘The Stlees which compose itmust be’preserved. fomZorropsion twashecenarytomakeprovisionthat they should beconstantly Penewed and maintained inasuitable state.eateneymarlonberenl atorpataofourbodessnthoseoflan Sodevenofthevestnec."Andthestructureof thse last 4mach themore admirable,onaccount oftheiramalnes, thatcehoul perectiy easyall therantswhiehhepeclasfoeach spin "Lat tnelaming Oly tho soooofseeingineeesory Byechtheydingobjectaoite,£93 Daratoecapeur eximination sigaothamen je discoverthesumeperfectioninplans;ev ‘hinginthemconcurs totheirformation,tothee ovis fonjodcn ofharoverof riteoroftheir seta.” Wht prodigy,to beholdsplattreysprngfromamalgralcast intotheearth,bythehelpofthenutritious juices ihwhichtetalaust”heprofane Poundinthe bowels ofteearsarenoIbswonder. (fils every part ofature fscapable ofexheuting ‘Ottulon powers ofreeeerch without permting {rio penetrlc althewonders oftxcomtractons | Nay, were utterly lost while weretoct how every ‘substance—earth, water,air,andfire—concurinthe Production ofallorganizedbodies;andfinaly,how / 296 QUESTION RESPECTINGthearrangementoflltheheareslyBodiefs90 Eateneee Arenttd semigoneSean tismanner,itwilbe CE nee er a naeteenmenwhomaintained, thattheuniverse‘wasRevdlofmere nce,wihowtegenBet fhetetmerechance,ehoanycei,Pat orihedatitaNorevebansknowledge 0nature,andwhomfearofthejustice Wr Bentchet ee nclnewednng issofGodespegreenromacknoyleing Him,‘who created the whole universe, and, from the re- Tanswn aeJbeetagenteTeriigettperfection,7neMateecreatedinSee xodneaeofmanseemstobe selene aaeens Sas Seager, ofheperoeatsWe ‘world;endtheseevilshaveratalltimes,spearedctoptie ihesr posesSod pepeiiereioteCo Fase Migseetes ecm eTSY jrele See en SedS Pepe etre d Ossiequestioneepectingtheoriginofevil—theaonyorcaome SowotbesBose thersanddivines,"Some‘haveer eeeeeasictiparatoh emer, thaminegonerestiat REPUastnhetWeSaoaaedaaa Shs"oplainoughtiobingo lepetaton"stese sotonstat neaandholinessofGod.Others,finaly,coms Sertagenioterywelneat tomprehets mdthese Taree es os sa onueut oF avi aor Godisvupremey goodandholy;Heiheauthor otiowort,and’ilarwordsarewithcrimestpparnlydictoreconebeinwyop, icaltoreconebuyinmyopinion, ‘agreat partoftheaigiculty‘vanishesasoneswe RESTobmod’jstidofopinadoftelbety orementia| toi that Gou Mawel cannot divest & ors quality. God Saving crated spits, andthe sous ofmen,‘remark, first,thatspiritsarebeingsinfinitely moretucallont than bodes, and, secondly, tht athe foment ofcain eawaraod fine IRvrequiite 12theformation oteelncunationnfhereltherefore,oodfiealynalingthatGodraedaia,"Butieingthoangeapintato Shoeotliertyovelegeopeteofseat withoutapowertosin,tocreate'nspiritpossessed Witteoveroflang hasnothey infopestent ‘rthainperfection,Seunvesptcoudnotbe rested dente oftat power ‘God has,besides, dono every thing toprevent crimes, byprescribing tospiritsprecept ieob; Sceanbe’Of" which mit aeays nde? tom pondSadhuppy,Thoreleoothe’metbodofresing Spates liccannotbesthjoctToanycontinSETiP omeofthemhaveabaoed elybenyaad ius thescommandment tnrein. steerigandworthyofnainens wit tay meat ofthe Dayanfheeramae ysosctionoreoecon. siderodnrvely,that won hve boon bate sot {Drereaie such Spins, ayGod forenw they nisttaeknseel. “ttsfarvaptoesuae, AinerstandingsforweKnownotwhethertheplan ‘finowordaldsubsistwitnotthems“Welw, ‘ofthecontrary byexperience, hatewickedness ofsome mon Trequcmly coetbuten Yothecones:‘oanamendmentofothersandthershysonducta them tohappiness. This consideration alone is 200° art 10 onmerime snffictent to justify the existence ofevilSores004Loechpoweroverthecomeequasoss‘ofhuman wickedness, every one may reat senured,thatinconforming fothecommandment ofGod,all ‘entswhichcomefopeas,howevercalamitoonthey Seyopertohm,arayesotthedveston orad‘oalyterminateihietroehap Pits providenceofGod,whichextendstoevery Rtistactory sluconofihequestion reepectngthe ationofonrespecting Permissionandtheoriginofevil.Thisikeweit Bre foundationofallreligion,thealone“objectof ‘whichisopromotetheesivaiionofmankind."> ‘chDecember,1700. LETTER XC. Connesion ofthepreceding ConsiderationswithRel “ReplyttheObechons ofthePhilosophical ‘GyeiemsegeinstPreyer. Barons1proceedfartherinmylessonson soontndpysicnfihak imydatytopotoa{Wyre comesion ihrenowerer ‘sndabeurdthesentiments ofcertainphlveophere ttybeheyte#0SoeFelelSrerreinsposoawicochewhack 4. whi!ienotconformable totheitsystemof _ FromtinsourcearedenedpontofthewotsaadKeresieninvligin.Severalplosophcal eysieme<tueeeiares mentee arenSesotho PeresrtgmpsSreeSeesepeaceva Soe camerraven. 200 sretoreligion;butinthatcaso Resotmen,ithepidofplosophersknewwhat Erastop"Rou?soundlinophysame timesseeninopposition religion,tatopposition intoreapparentfasral;andwemurntuly CurselveeYobedazziodwiththeepeciousness "ieeta with considering onobjection which l-oat‘Athepilospiea apsefavestated‘ageinst prayerReligionprescribes thsusourAfty,withanassurancethaGodwlhearandsn-‘werourvowsandprayers,provitodtheyarecon- {ormable to"the precepts whichhehas given Us, Philosophy, ontheother hang instructs usthat al frente ake place jnstrict conformity tothecours ‘ot'nature, established from thebegianing and thet fur prayers can effect nochange Whalevéry tnlaaswwepretendtoexpectthatGodshouldbecontinuallyTalsoectioneothopreteryeyhataagion isobfectionhasthegreaterweighttutveigion TeelteachesthedoctineofGodshavingea lishedthecourseofalleven,andthatnothingean cometopasobutwha!Godforesawfromallter. igsTlrele,sayheobjector,tatod shoud think ofaltering thissetled course, incom-Bltacewithaypayeewhichmennighations ‘Bot remark, fst, that whea God éetablished the course oftheuniverse, andarranged alltheevents ‘which must come fopase init, hepaid attention toalthecircumstances whichshouldaccompanyeachrent; andparca tothedapoitony thedesires,andprayersofeveryintelligentbeingand{hat thearrangement ofall vents was disposed in Retest, ary withlien Gremtaneen, + ,thereforeya an addresses toGod aprayer‘worthy ofbeingheard,itmistnotbeimagined thatauchprayercamenototheKnowledgeofGodt _. y 300 anmiy To onmncrmns. themomentwasformed.‘Thatprayerwatal- utyheardfromaetety;ailtheFatherof Hlorciesdceneditworthyofbeingunawered,hea angethewnexpresslyiafavorofthatprayer, that theaocompllaimen shouldboaconsequehes Stine natural course ofevent Itthus hat Godfhaverethepayeroftenwithoutwerkiag'8mince,"Theetablishmentofthecouroftheuniverse, fiedonceforllfarromrenderingprayerunnccee: fy er teen atantlerbyconeying {2sticomoltoryrahtaalolepryertane beenalready,fromthebeginning,presencdatthe fet afthe iron oftheimgaodShathoy fhve been afimitied fto theplan oftheuniverse,se Thotires conformeblytowhicheventawere10°be Togulaied,insabeerviency totheinfitewisdomof Be Creator ‘Can any one believe tat our condition wonld bebeterGoldoebnoldgeofoupaperste {orewepresentedthem,andthatHeshuldthenbeGepovedtochangetncurfavourtheorderofthe couseofnature’ Thismightwellbeireconclls fietohinwislom,andinconsiatontwithhisadorabe perfectons. ‘Would there not thn,bereasonto Boythatthoworldwas8verytaperectwork?hat Gtawasenielydponed0befavourable:tothesith menbtftnnn rece therwasBhcounotek lewereeen tellytodisregardthewantsoftnteligentoinge, sloven contethepanapatot Theenlvere!Fortownatpurposecreateiisme-terial worl, repleniabed with Zomany great won- dorm iete were nofateligent beings, capable ofSdmiinginadofbeingelevatedbyitoteadora-fonofGod,andtothe‘moetintimateanionwith {eteGresar,in which, undoabtedy, ther highedt Selcity conus? mente oF terniiionnr amos. 301 Hence, itmust absolutelybeconclnded,thatin- telligentbeingsandthersalvationmusthavebeen theinal objectnanbordnaton towhchGed regulated the arrangement ofthis world; and we have every reasontoretassuredthatalltheevents qedSlePiesinaretnthemateligi FetmonywilheanofalIneigentbey{o-contct themYoTheirtuebappinea btwil ‘out constraint, beeause oftheir Hoery,which ia8fave apneaextensionitoDaly.Thereie'therefore "no.grountforsurprisethat‘therehoabnntelgetbeingswhichsaleverrachity.TatUieconsezionofspiritswithventeconsists theDivine Providence, ofwhicheveryindividual has the consolation ofbeing'a partaker; 0that very man may rest assured that, from alleternity, freentered info the plan ofthe universe. How Oughtthecoaeraiontotemasgrcoaenee ourjoyintheprovidenceofGod,onwi Feligin1sfounded!"Yousee,thedyhat”ontha sidereligion“andphilosophy arebynomeanaat variance’ 3dJanuary, 1761. LETTER XcI. ‘ThaLibertyofIneligentBeingsinHarmonywiththe etieoftheCortonReligions Laneare isaquality 20ensentialtoeveryspiritual blagthsGotimaceaaotdvtheofutashecannedaboofexteninoFate frertie, without entlydestroying oranti istodivestaapintotibeln‘wouldbe thesamething'astoanniiatei"‘Thismustbe Understood oftheepritorsoa!itseif;andnotoftheActonoftheboywhichtheaoldirectsom: aie 202 LIBERTY OFfeetyowt, preapetmsfom tryoiileuroevnmefomTigoutresundayroeepeoriagees goal at eyofsoptedeofByte,Bikeeeandonutatornyat seca sean tty dag bern cod ys, digi etemn tcl,eoing,Reng Ses eet ye nmiofa. eeeri lot ery tee Sirersare rete ccon yseas ate eoncetera comporem,EeeEn th ed, tion,orwatmightbeposto stmotives eoulmi ota Rithoutemploying saymannerofconstraint:Tow? everpower‘thesemotivesmaybe,heisalways Pratermistc meee sie oreFayeee deerateayoe,Roraycaees Spoon lla Sr ST ee raf tearteeepring,etyofpe season ena coteeEp seriaens caBait Sten ey me ero te ars sienna vats rt, fant Sy veepecseee werettionnt auixo8, 208 persuasive motives; andIbeliove that all pomsibleBasesareadaptedbyProvidence toourcondition,euchamannerthatthemostabandonedwretchesfight derive from them themost powerful motives {2Sonvernon theywouldbatten fothe:andhatamiraclewouldnotproduceabettereffectonfeavious apna: theymightboaed by1forabmntlwouldttBeaunebeter,1&a co-operates inour conversion, Dishing uswith motives themost efleacious,abby {Recemafancen andopportuntin wohHsprveTf,forexample, «manwhohearsanawakening sermon isafected byirepent, andisconverted, the set ofhistoul fsevidently hisOwn work but theoccasion ofthe sermon, which hewas80happysetbearprecyatthLinwhetHewan RieDigsProvidenceoverruledthatctreumotance, fosalutary tohim, Infacty without the oppor: ftnty, over which theman hadnopower, hewould have peraated ina sinful course,lopeyouwilsonycomprehendtheseaing ofacledpentionnaytineMancandonhing ofhimeeify allcopends ondivinegrace’ itie {hat workeih towil aod todo." “The favourable Circumstances which Providence supplies to.menSeauficienttoelucidatetheseexpression, withoutHavingrecoursetoaecretforee, whichectsbycomettraint onhuman Uberty; asthees circumstancesBerostedofCo,eoaormy foietoecon fummate wiadon), itheview ofconducting every {intelligent being tobappiness andsalvation unlessbowilfullyrejectsthemeansbywhichhemight haveaftained traefeliity.® uhJanuary, 1781. ta hag et8 06 suvowamion muspaorine ' LETTER XH. Blecidationrepectng theNatureofSpirits+tnondermoreclerty10elucidatewhatIhave Juranidfeapscagheliferoncebetroenbuytndapirit—forit iimposibletobetooatentivetowhat cationtadiereceaixed at ‘olhingincommonwithbody,nor SF opine td neceearytoeojolnthe Extension,merit,andimpenetabity arethe Witbece borkwilnott lmpen ‘withoutsnertia,withoutimpenetrabiity. Allphi:Toeophere areagreed. tha! extension cannot have Paveinvengectetspit"Iheelevenrth, forveryihgextendedisdivisible,andyoucan formtheideaotispais;butsspiritinusceptibleSultorotis tadparEveryoittsesomplots orofi onybeing,totheexclttonofallpare,icannotthen teedirmed that spit has length, breadth, oFthickness, Ta8wordallthatweconceiveofx= tensionmustbeexcludedfromtheideaofaapniTen appt, eer thu pitahave maguitode,theysustresemble.geometrical points, Ee"detain Oiwithita hyhavealtelength,breadth,nordepth,"Woulditbeavery cchrateIdea16representtoourelvesaspiritby&ESubematiel pointfhewhelaniphilosophers faveprofeasodthisopinion,andconsidered«pirioetsignatelyeaaroteontbeDerrofutagndovedhennemeiie ftansportthemselvesfo"aninstanttothegreatest inanoos.Theymaintained, thatinvirtueofthis xtreme minotonees, millions Ofspina might be sum warns or srmmms, 308 tectovdiheslwpace;heyevenmaia on,Howmanyspritcoulddanceonthe ton"According toeyalltdiaecom otparticlesextemelymite,divestedofslmagu>fdo-andtheygivethemthenumofmounds’ASonad,then,msmobwancedestituteofallextenefiom;todohdivingabodyfilyoucometoparticles20minuteanfobenegeoptbleofwofartoer Aivision, youhavegottotheWalffan mona, which ; ‘ieriets omteontslept unt ony inthi thatthe minatest particles ofdat fotfrp licen eladtatsor ‘Tito isll necessary foobtain real ona, Nowscoring foMzWalfot slyaisarecomposedofmovado,buteveryspitme nomad andtheSuprome Being,{tremble an1 ‘rite isis iewive attonad, ‘This doesnot eoavey T'rery magnseent Hea ofGod, ofspi and of theedule ofmen. T'eannot conceive that myeoul Bvootting more than abeing somlay fe tat Faiticles 6a body, ortat i reduced almost toa Boi sper to.elesapo ting Fahne Katerr alndtgterwiht formabody,xaipofpaper,forexample,tolighta Pipeofttacco,"Batfaesipportersoftisoptionpitheground,thaa'scprbas00augerSentutFecha resemblespometeal pointLetteexaminethesobtyofootexeofremark,rst,thatanaapritinabeingofanature totallydiferentromthatofbody,ittabaurdto Spayltland whiehmop maga, nd EYcone, woudBoflyfahow tmanyfectorincelongaspitiorhowmanymaooraeiergaly 10.tingewhichhavelengthOF weindeaeaeaiepeakingofingit "e 06 areasoFsrs, reretobesaked,howmanyfetlonganourwa, orbow itweighed.“Icanfconfdentiy afr,thatanHoutisnotequaltoalinefahandedfectoroftenfeet,oofonefotFwy ‘therstandardofmeasure;butitbynomeansfol-owsthatanhourmostbeageometrical point.Anhourisofaatureentirelydiferentandi8impoe-tiefoaltoaywandawhchmepoce& Tenethwhichmaybeexpressedbyfetorinches,"Thesamethingholdsgoodastospirit.Icanalwaysboldyfirm,that£epintianottenfeet,norahundred feet nor any other numberof feet; but itdocenothencefollow,thatxaptispointyany.‘morethanthatanhourmustbeone,becauseitexmotbemeanuredbyfetorinches."A'sprithen,inok monaoranyepeetimateaaa Fariclesitowh maybedivided;undyou Ereperfectlyabletocomprehend, thataspiritmay tive noextension, without being,onthataccount& fputaramonn. Wemontesarepuns every ‘ofextensionfromthatofepi “TouatyInwhatplacedoceaspritresdetwouldbeforthesameresnon,keineansbeurdquestion,{G10comaectapnwithplaceitoteriexte™ tiontoit.Nomorecan{sayinwhatplaceanhow {tythoughassuredlyanhourissomething; someShagetfsnyexitwihtbeingtached toaertainplace.1can,inlikemamer,firmthat ToadtorinanyparcaPacewitioaabeing orinany ‘without deducedaaconsequencethatmysoulbastherefore toexintencejuntasitmaybewithtruthaffirmedSeboaraopang,ttexttherinayheadnorontofmyhead.Aspinexist,thea, $Booghfinwerepiscesotourrebection {urnontheperhichaaithsofsctng{odyteanamostundoubtedlypronei bre. Sifsoulthe,doesnotexitinaparticularplace, STATE oFsouLs arven pear. 307 butitactathere;andasGodpossessesthepowerofactinguponsiloan,ntienpectweway Hriaeverywhere, thoughhieexistenceiattactornoplace.101k Jemuary, 1701. LETTER XCHIL The Subject continued. Reflections onthe State oSubj Refetn f ‘Youwillprobablybeéurprisedatthesentiment which Ihave justnowvested toadvance, that bpisi, ini oftheirature,aeInnopace,In iming,Ishallperhapsbein foramanwhodenies the'existenceOfspin,and ConsequentlythatofGod,ButThavealreadydo- Tonstaedhatsomething mayexis,andhave& Fealty,witoatbeingaltichedt9anyone,place ‘Pheexampledrawnfromanhourthoughfebe- ‘movesthegreatestdificulties, thoughthereisan Inaitediference between anhourandaspirit. ‘ThidewhichIformofspireappears9meSoatllertndttgeomet! platesndwhore e ma jelpoints,andwhore- ‘daceGodhimself totiaclan.What eanbemore stockingthntoconfoundaligpsantheSox meBeingamongtherest,withtheminutest Eeien intowhich&bodyisdivisible,andfoTank featintheoameclanswiththeepuicle,whieh Jesnotinthepowerofthelearnedtermmonadto‘ennoble!"Tobeinacertainplaceisanattributebelonging‘only tocorporeal things: andasspirits areofator{allydiferentnature,iibnotamatterofworpriseto fy;thaltheyaenttobefoundinanyplaceand Ffundersoaprebomnlonaropatheela ‘idationswhichhavesubmittedfoyouonthisub- 208 REFLECTIONS ONTHESTATR Jct. ItthusIexaltthenatoreofspiritsinfin aioethatofatin md ‘Every spirit i»2being that thinks, reflects, ea tons, deliberate, ats freely, an, inone word that Iiver: whereas body has noother qualitiestutthat afbingtends,nunceptbleoftin,andne Denetrable, from’ whence resulta this "universal {uality, thatevery Body remain Inthesame state Srinng asthere lsnoeceesity ofmutual penetration,oroftheirundergoing somechange; andin‘aneofthenecessity oftheirpenetrating eachother,iPiheycaineemaheirsaetel pen ijesthepowersreat EEingethestat,ueartolebocoeenytopro- ‘entalpenetration, .Inthisconsistallthechangeswhichfeplace,in bodies:allispassive, andnecessarily befelsthem {inconformity'%0 thelaws ofmotion, ‘There i ody, nether inteligence, nor will, nor iberty:{Seaaetheeupreminent ainofwi,while toient arenunoepie ofthe itispirit likewise, which produces inthe cor-porealworldtheprincipaleve,teilostrionsac-Tone ofintelligent beings, which arealltheeffect oftsiniente witchfbtlOfhenexereog Spon‘thetbodies. 5,whichev bisoverisbody,cannotbutbeSonsideredasgit .ofGod,whohasestablished thiswonderful uniontweensoulanbody.Anda81fndmysoulitoch 2union with scertain particle ofmybody,Senostheamayatateet mysoulisinthatspot Sheyhyovalrosin, wowbere,fellsrereto {hitpceomybodyonlyinvroftsaetion andl itspoweritialsotheinfuenceofthesouluponthebody‘whichconstitutesitslifewhichcontinuesselong|4sthisunisonsubsists,ofaatheorganization ofthebody remains entire." Death, then,isnothingelse orwovearrenpears. 208 butthedissolutionofthisunion,andthesoulhasno heedtobotransportedelsewhere; for,abitrides Eopaceallacenmustbenigrato‘and, consequently, fitehoulpeaseGed,atermydeat, {o ‘enabiah&newunionbetweenmysoaandal frganiaedbodyinthemoon,Tshoulinstantlybe {nthe moon, without thetrouble ofalong jourey. povec'yer srengasisedvoyiepcefsold eroveran infhemoon,Be'equaly hereabdinthemoon; apdthisinvolvestoanyfearon iaolywich ‘cannotbein‘twoplacesatones,butthereishothing toprevent spirit, which hasnorelation ‘0pace,favirtueofitsnature,toactaltesametime‘on‘soveral bodies, ntoated inPaces very remote Eaneacheran inthe espace gitbe uid,withtruthdatitwasinaltheeplatesat ones.: anionicofGodstaispowereons onteofGod:itis re {otheoleuniverse,adlltheUicewhich Contains itappearstome,ofconsequence, ani= expression,10sny'thatGodexisteevery- Whore,astheexistenceOfasprithasnorelationqo'puace, Itismore consonant with proprietyto FyGodieverywherepresen us now compare tha idea with that ofthe‘Woltians,who,representing DeityundertheweaofZpoint,eilachHimtoonefixedplace,a,infect,& paintchnnotbeinseverplacedstchce’andhow Brit posible toreconcile theDivine omnipotence within idea ofapoint ‘Death being4ditsoltionoftheunionsubaating betweenthetouladbodyduringlife,wearoen: Aledtoformsomeideoffhestateofthesoulher death,Avthesouldaringlife,derivealtsknow fedgethroughthemedium’ofthesenes,beingde= ieee oughtemeioiomenin Eironghtbesenses,it00longerknowswhatin S10sevenoussoeomret200 passing inthematerial world;thisstatemight,in range ealetiaemigfaSeeioea oatoeSpel hem fecae oe, eessega Seatac ies eeetematefeces oepepo pepe sceSra eeergy ale alr he oft enea Fale en nsweacostingWis oneBrrroe BrattrenSeyeeotme scictchoneenemepoeEe titted oo oes Beet bemeet be at . Behe ae endikPewee ieae foundsleep, morerogularandconnecte eetoeeegecome iy Sateenhea at yerokephgey Coetchan hehngsaeweecon Sepeeel corcaminetdmace,bey SEAS Seisa geee == Sous. erren xew. omannhstneSpntDo nsaiAcettm beenhpcppateoeng 4afhighimportance! thorogtly toiaveeuigntg ia scTION OFTHE s00L ON THE ROUT. 311 ons.Youwillpleasetorecollect,thatthe ctionUetreenthewoulandthebodycostingwe, {oidinfuence; bythoone,thesoulperceives and feelsalthatpasesinacertain partoftebran; fii bytheother iasthe power ofstingonthat fameportionofthebran,sadofproducingcertain ‘otis inte‘Anatomists havetakeninsitepainstodiscoverthiaotherain,whichjotelleteeat fhesoul;notthattesoletalesdesthere, forit innotconfined toany pace, butbeestse inspowerofstingisatachedtothatspot,Ttmaybe Igthatthosoulfspresentthere;butnotthat xia there, orthat ftexistence iUnited tit ‘Pais part ofthebruins undoubtedly that wick {ilthenerves terminate now, snatomiata telus that this termination inia coin portion Ofthe Eratoy'which they tern thal body” They Therefore wemay consider astheseat oftbeaout; tbl theCrestor laabested upon eyery ou! sockSpowerover thisealousmembraneofhisbodythatAton pret panestraie triveable10producereciprocal Here,Then,we‘observeatwotoldaction:the"one,by swtich theboty sets upon the sour~and the oche,Uywhichthesoul'sclauponthebody;batthes +dona’ areifitely tern from those: whieh Borie exercise poo other bodies "Te oul front union with thecorps calla,fais comecedwitwhclbody, EFmensofhonerveswichaothenceunrorely Elrased.Now,tenervesarofiressowonderflly onstracted an 0allappearance fled with Bid 0'sbtlo, thatthe alightant change which they un.flagneextremlyialycommited fotheomerextremitynihebein,wherethesectofthe sul ns "And, reciprocally, theaight m= pressionnaebytheaoalontheextremitiesoftho Bervesinthecopurcalor,inionmediately wane 7 818AcTIONoFTHEsoULONTHEBoDr.mitted thewholeextentofeverynervesSatistwatthoclesandmembersofCar‘bodiesareputinmotion,andobeythecommandsof.thesoul.‘Thiswonderfulstractureofthebodyplacesitin 1very close connexion with allexterior objects, whether near orremote, which may act upon it,eitherbyimmediate contact,asinfeelingandtast- ing,orbytheirexhalation,asinsmeling.”Bodies atgreatdistanceactonthesenseofhearingwhentheymakeanoise,andexertinthesirvibrationswhichstrikeourears;theyactlikewiseupontheSightwhentheyof‘lumined,andtanainto Oureyesthera} whichconsistinlike fmenainscornvitocated"Tnthatme iummuchmoresubtilethantheair,whichwecall ‘ther.Itsthusthatbodies,bothnearandremote, ‘ayactuponthenervesofourbody,andproduce‘certainimpressions inthecorpuscallarum,fromwhichthesoulderivesitsperceptions.‘From, every thing, therefore, which makes anim-resignonournerves,thererewutsacertainchange ‘thebrain,ofwhichthesoulhasaperception, andtherebysogiretheideaoftheabjectwhichcaused it. Wehave here, then, twothings tobeexam-fined:theoneiscorporeal, oFmaterial,whichistheImpreasion grthechange produced jnthecorpusfanumofthebrain;theotberspiritual,namely, :{theperception,oftheinformation,whichthesoul derivesromisi,iTmayaoexpretemysell ‘fromthecontemplation ofwhatpassesinthecorpus calloram,thatallourknowledgeisderived. ‘You must permit metoenterintoamore titydotallhisimportantale.”Letumdet, ‘consideronesinglesense,saythatofsmelling, ‘whch,beingheleastcomplicated, ecemethemost EeePotnersensesanthilaed,andthataroeewas| appliedtothenose;itsexhalation wouldatonbe ACTION oFTuE soUL ox THE BoDY. 313 ‘excite xcertain agitation inthe nerves ofthenosewhich thence transmitted tothecorpus callonum, will ‘ccaion there likewiae some. change and fnthis =etheaiarcamntane mice sabe etoourrengution. Tisaightchange,Pro odinthecorpuscallono, isthen percerved thesod,anditthenceacquirestheidesofthesmell fof rong; andthis isthe rival operation which fanlace btmesma!Ex whatmeer lone,anitdependsontheincompretensible unionwhichtheCrestorhasestablishedbetweenthe ody and the sou thecorpsalan iexcelthewalthethere isexcited in‘eaoftheamlotaroseorthecontemplation of thin change furnishes tothe wou! acertain idea, that ofthe smell ofarose, butnothing more; forathe other senses aresuspended, thesoul ean form n> fdgment ofthenature oftheobject itelf which uggested this idea-the idea oftheamellof rose Alone was excited inthesoul, Hence wecompre:hhendthatthesotldoesnotformthisideaofieelf for iewould have remained unknown but for the Presence ofarose.” Bat further, thesoul isnot in- Liferent with reapect toit;theperception ofthis |eaisagreeable; thesoulitself fssomehow inter:tested init Accordingly, weeaythatthe soulfeels {ecodour oftheroses ad’ thie’ perception wecall section, vieieeaewihatheoersean: evry objectbywhichtheyarestruckexcitesintheCalionenacornchange,whichthesoaooverveetwit asensation agreeable ordisagreesble, andfromhichitderivestheideaoftheobjectwhichcaused Fu"Tale iden accompanied with aseneation 90uchthestrongerandoreintone,esthepres.tion made onthecorpus cllaum istaors lively. It ithan thatthe sou bycontemplating thechangesBreconthecorpsaloufthera,sequeneet 314 ras racuuris oF Tax soul, ‘eas,andinaffectedbythem;andthisiswhatwe ‘understand bytheterm sensetion® Th January, 1761. _LETTER Xcv. OftheFaculties oftheSou, endofJudgment. Hapwonoothersensebutthatofsmelling,our knowledgewouldbeverylimited;weshouldthen Ihave noother sensation than that ofodours, the diversity ofwhich, were itever sogreat, could notTEuchinterest”oursolbingrestrictedto iathatagreeablesmellswoul ‘someiesofploarareandsuchanarednagrecable woul Excite some diagust,‘Butthisverycircumstance carriesusforwardtoSonesgress,aodapetberdogstiogItcus smellisle,andanother disguston Dotbeamatier ofdoubt, that agrocable smells. ex- ie inthe corpus calloum adiferent agitation from {hatwhichiproduced bythedhngreeablo; bathhowcomesitthatoneagitationinthecorpuscallo- ‘rum can give pleasure tothesoul, while shother is Offensive, and even frequently becomes insuppor.able’Thecauseofthisdifferenceresidesnolongerinbodyandmater; wemustlookforitithe tue ofthesoul itself, which enjoys acertain plea- sure infeeling certain agitations, while others ex:k iteuneasiness;andtheFealcauseofthiseffectwe3 Go-not know.‘Hencewecomprehend thatthesouldocsmorethansimplyperceivewhatpassesinthebrain,ot tervalcalories iwtjine ©senationsjulgueatTeepocting whatitfadsagreeableordisguating, and whetrneldliothesrshsenacingLets EESiparcioeamtswehyaesseende AND OF JUDGMENT. a5 consequently exercises, besides thefaulty ofper-tcetving, another andadifferent fal, thatofdg. ingsaithindentin wholerent romtho simple ideaofasmell "hesameconmideaion, oftheeneofsmeling api,acorn alotherctoftheout Whentheamellarechanged,whenyouspply10 thetonescarnationaftersrowstheod!hisbotonly’perceptionofboth smells, but likewise te- ‘marks #diference between them. Hence wecon clude,thatthesoulstillretainsthepreceding ideato.comapare itwith that which follows: iathiscon: +sitermanzeer0memory,bywhichwehavhe Ferrerofreclingeaaniscadentandpal.Now {herealsoareeofmemoryisentirelyconcealedfrom un,Weknowwellthatthebodyhasmachto40 init;forexperience nesuresun,thatdisease,andasoscienwhchbetaheodyweakenandentlydestroythememory:itinequallycertain, Atheminetimethattherecollect ofteasIe theproper work ofthesoul Arecollected idea is fssentilly diferent from aaideaexcited byanob-Fok,diepateecaectnaftennwhichaoda ttn ray fermmtat which ThadwhileTwaslooking atthesun. , “'Some authors pretend, thatwhen werecallan ideahorehappensintbrantnagiaionsilar tothatwhichfstproducedit:butifthinwerethe fc Ishould nctually aoe the sun; itwould 0|ongerbearecollected idea.Theyadmit,indeed, that theagitation which accompanies therecalled . idea ismuch weaker than thatfrom which teoig-halideaproceeded: butstiltamnotsatisfiedwith this; fort would thence follow, that when frecall the ideaofthosun,itwouldbemuchthesameax ‘when face themoon, thlight ofwhich, you wil Jswe,6,remerber isabout200,00 traceweaker‘hatoftheaanButactuallytolookatthe -.- 7 316 ras racourmes oFTax 2071, ‘000,ansimplytorecollectthewunaretwothingsSootydite,"WemaysaywithtrththattherecollectedideasSapectsonlyteoolSAopetefyte . tsonythesoul; ebody, Setoe!ideniaccompaniedwithscertainagiition inthebrain,whereastherecollected oneisdestituteezine wooytastonwih fakewiseoatectsctlagonmyeccgedtitow {titysuissensation,butitcanwithDopro-ovacolect andtofelalweyarematawethings ecoremalntwo abeoluelydiferent.‘When,therefore,thesoulcomparestwodiferent smells,whenithartheideaofteovefromthe fncoofanobjectacting’ontheseneeofsmelling, ndthatoftheotherfromrecollectionthasinfagk {woideasatonce,theactualideaandtheTecolIectedidea,andin'pronouncingwhetherofthetwo iorsorevsgreatieordangeriexerignParaaclGnromatbywheonlyateplats whatiepreseta Baiheaopronewaloroperations,when asuccessionofseveraldiferentmal {Ror we stackithachoftheynt igare and anotionis herbytegutedSfpasaodProsea,andevenof fhoweofhichihenalveodytad t ‘whiehhas xperience, tharwindenethraofsxcinastochasitundergoesev ‘acces.tively;andhencereelstheideofduredom,endoftne.”Finally,onremarkingthediversityofwearSalonswiheycoedeaslerbogiereckon tne,te,three,0thooghthinshoudnotgofar-{r, fom want ofsignsornamep.wherewith to tmark oumbore. For supposing«manhasfstbe: frfoex,andwhohushithertoexperieoed ‘v0 SensationsbutthoseofwhichIhavebeenspeaking, ‘xp orsepoxex n7 farfrom having created alanguage forhimself, henlyKaowshowtoexerthisftfacullesontheSinpleeanwhichthsenseofsmeling presenta weegaehe, attheanqetionana miredthecapacityofformingtohimee Teasotaveryofthepresen,ofthepstandeven Ofthe future: afterward, ofsdocession, ofthe da tation oftime, and ofnamber, oratleast oftheele. Tents ofthese ideas, Some’ authors pretend, that |ucha'mancouldnotacquiretheiea‘ofthedura:| Hon'ot time withoutasuccessionofdiferentsen- tations;butiappearstomethatthesamesenna: fion,thesmelloftherow,forexample,beingcon- Lined foraconsiderable time togetherhewouldbo tierentyaectrd byithanhe.wouiwore Presentlywithdrawn. Averylongdurationofthe ameseteation would atTength become tiresome, Which would necessarily excite inhim the idea ofaration.”Itmastcertainlybeallowed,thathissoul‘wouldbesensibleofaverydiferenteffectifthesen-ation were continued tong, than itlasted only for ‘|Smoment; and thesoul will clearly perceive the difference: itwill accordingly have some iden of ‘duration andoftime,withoutanyvariationofthe | Sensations.syturerefesions hihioumaen cond itssennaione, arewhat.propery belongto.apintuaity, the body furnishing oaly simple vensa-ons:heperepllont theseenaxionslwready fanactofthosoul's spirituality; forxbody can POUYanary8hemery Das a8 ovrusweauers, LETTERXCV1.CrnectonoftheExistenceofwhatwepercerebythe yoannakvaythRahoieapaod alate. _Inallthesensations whichweexperience whennefoseinsuckbyanyaeiit alterofhighImportance toremark,thatthesoultotnlyacureaundeaconformedofbotmprension Tiaothenerves,tuhatitnen,atbeeae time,there must existanexteriorobjectwhichfur- ishedthisidea.‘Thoughbabitmakesusconsider this judgment asextremely natural yet wo havereavontobeastonishedatitywhenweexaminemore‘itentively whatthenpassesinourbrain.“Anexamplewillplacethisinaclearlight.shall supposeyoulookingatthefullmoonbynight;the ayewhichenterintoyoureyeswillatoncepaint 1theretinaanimagesimilartothemoon,fortheflaue‘preaofforetinarebythayepat Kitavbrationsimilarthatwhichagatethowe ofthemoon."Nowthereinabeingonlyacontex- ture ofnerves extremely subtile, you easily com-Drehendthattheeenervesmust’Benesundergo’8Exrainaghation,whichwilbetara1the ‘originoffhenervesinthebrain.Therewillbeex: ted, therefore, ikewine intha! portionofthebrain ‘ceriainagitation,whichiatheealobjectthatthe oul contemplates, and from which itderives a ticleofknowledge,whichistheideaofthemoon,Consequently,theideaofthemoonisnothingelse atthe comemplauon ofthiswightagitation seeoriginofthenerves. tneactirityofthesoulfe#0muchattachedto thespotinwhichthenervesterminstethatifabao-lelyknowsnothingoftheimagespaintedanthe eoters, ax waranuatere, 218 begofrycalmocesof esl ef ao rhewaster pedicnare, Thewal borers Sees eat moon ee SESS SYShsepie mene, feed heln NE sng sure enasayicraSareeerin Sane ise nothingevenoftheimageswhicharetheimmediateowing senofhemageswhearsimple ‘thatthereisatthe‘bottomey,eyeaontHye muhen ie he Beanonghmeean, eastrei cocina ahr EE‘causeofsuchimpression, andthatthisbodyistheee TF nr agnorsodStich a ee etsguitcke Stan een ee ‘undoubtedly certain, that inthis wedeceive our-sedicrnaliewedees,oor i Rie ere hereais 320 ovTHEWeaLueTs, ETC. : osophers have lost their way more than oncein endeavouring toavethisiii.»vejustoa moontakes acealrepotoalthebodewichwewe. ‘consequence isnot apparent,thattheremust ieodinotofom,teinsom:ranmdergonn nsorimpressions. Thisapplieseven. {toour own limba, and toour whole body, ofwhich‘reknownothingbutbymeeoftheteen,andoftheimpresions whichtheymakeinthe. Brain: if,then, these impressions, andtheideas which the falderive romthem,provenothing attheex-{tenceofbody,thatofourownbodybecomes Stony oubetl "You will not therefore:-be surprised, that. there shouldbephilosophers whohaveopenlydeniedthe ‘etistenceofbodies;andintruthftisnoteasyto efutethem,“Theyderiveaverysrongargument fromdreams,inwhichweimaginethatwesee90 manybodieswhichhavenoexistence. "Itisaid ‘with trath, that then itispure illusion; butwhatAssurance havewethatwearenotunderthepowerof«similar illusion when awake? According to thesephilosopher itisnotanillusion: theBoul theyadmit,perceivesacertainimpreseion—an idea; uttheyboldlydenyittobeaconoqunce, thatbodiesreallyexistwhichcorrespond tothoseideas.‘The supporters ofthis system arecalled idealists,becausetheyadmittheideasonlyofmaterialthings:and absolutely deny their existence, “They may likewise bedenominated spiritualiee, uathey maine falthatnobeingsexistexcep spirits ‘Andaswedonotknowotherspiritsbutby ‘meansofthesenses,orofideas,therearephiloso- DDherswhogooofarastodenytheexistenceofall ‘Spirits,theirownsoulexcepted,oftheexistenceof Tileeveryonetscompletelyconvinesd, Theos ‘tecalled egotists,becausetheypretendthatnothing ‘Satabthourownsoul mevorarion oFTae esters, Bt To them areopposed thephilosophers whom we | denominate maceratory, wa deny te existence OfSprit and’maintain thateverythingwhichexinaEPimatier andthatwhatwecalloutsoulinonlymatterextremelyaubileandtherebyrenderedcape- Biot tought Sth Jonuory, 1701. LETTER XCVIL. Refetaton oftheTeel, 1wanitwereinmypowertofurnishyouwith thotranocesory 1cbubel theWea andthe fgotnt, bydemorytrating, thattherein areal eon. Erion bothoenourscneafonsandtheobecinet elven which they represent; butthemore1unk ofithe more Ifeel myown incapacity.1woudberidiculoustathinkofengagingwith the eotita; for'aiman who imegnes healoe ex:fataandwhodoesnotbelieveimyexistence,would Sct'in contraction tohiown gyatem ifhepid thysialon tomyemia, wc,acon i,would‘bethat‘ofantaginary’BeingTtit [bie ahd fan conteheeat Isiapoestble foconvince ofthe existence of bodies fmcael determined todenyiToophhosuchphiJosophers existed,itwouldbehighlyta- terestingtobe’able10.convinceourelventatas ign ofoareval oxperinces smwatons isey$0 ‘wihcertaintycooeiniedthatbodiesUkeriseexit; ndthat,whenmyaotlinafetedbytheanaation ‘9fthemoonmaythenceboldlyafrtheéitenceButthetnionwhichtheCreatorhaseatabished botwoet topul andthe bre ist myetary 40Une fathomablehatallurKowiedgeofitamounts alytot:certainimpreseionn nadeinherua, a REFUTATION OF ‘wheretheseatofthesoulis,exciteinitcertammryiatis tentnacetote ieaavam rte aa nies Ease rica aria ane Sereeescaea aee SiGoenipeel were Se grecrsmuar anes ame i ‘tobetieve thatthereexists,outofit,somegbjectSih Saeed discovers tousseveral propertiesoftheobject. kg aoe wen akace neta ea tet ieee eeae SES acneca, iiaural aevemana mac ‘ena 3Drees,"Thedogtalburswhenbepoemeie Szeitesinhimtheideaofmype dog, Eonaoe ieoeer eet SihGeisbevamrre Serratia ane sommes a r :Ris rapstceneraiacuaepressionsmadeinthebrain;theysupplythe,soalEne aan oaeet are toonce Orgareaioreesgine Guam eaFEEonetnetre Propereater 1relrelationbetweentheiaipreasions ofthe ‘THE eaLisrs, 323 andtheideasofthesoul:itinenoughforuetoJknowthatcertainimpressions madeinthebrainex-sitecertainteasinthe,youl,andthattheseideas aerepresentations ofobjectsexternallyexisting, Henemeeslater ae ‘Thus,whenmybrainexcitesinmysoulthesenea- tion ofatree, oFofahouse, Ipronounce, without hesitation, thet «tree, orahouse, really existe out‘ofme,ofwhichIknowtheplace,thesize,andotherperties. Accordingly, wefind neither man norBeastwhocallsthistruthinquestion,Ifaclown should take itinfo his head to conceive ‘such a doubt, andshould say, forexample, hedoes notbe- lieve that hisbail’ exists, though hestands inhis presence, hewouldbetakenforamadman,andwith foodreason,btwhenphilosopheradvancenachfeotiments, heexpects weshouldadmire hisknow‘andsagacty, whichinfnitelysurpasstheap- rebensions efthevulger. Teappears tome,accordingly, abundantly certain thatachextrayaiat sentiments wouldneverhavebeenmaintained, butfromprideandanafectationofsingularity;andyouwilleadiybeliovethatthe commonpedpleave,inthisrespect,muchmore {goodsensethanthoselearnedgentlemenwhoderive hhootheradvantagefromtheirresearches butthat fofbewildering themselves inalabyrinth ofehimo- Tas, unintelligible totherest ofmankind. Letitbeestablished, then, a8certain rule, that‘everysensationnotonlyexcitesinthesoulan'idea,Dutshows it, 1maysoexpressmyself,anexternal object, ofwhose existence itgives fall assurance ‘without practising adeception. Avery formidable Objection, however, isstarted against this, arisingfromdroamsandthereverieofsickperons‘which thesoul experiencesagreatvarietyofsenaa- Hoonteberhichnowhereexiat.‘Theonlyre- ‘ectionIshallsuggestonthissubjects,thatitmust bbeverynaturalforustojudgethattheobjects,the 7 ; oy yAcuLTYoFPEnceTrine.sensationofwhichthesoulexperiences, reallyexist,ieirejueaferthnmanneovenle,Hou thenwedeceiveourscives:butitdoesnotthencefollowthatwelikewiseSeceiveourselveswhenweareuwake,“Inordertoremovethieobjection,itie‘eceasarytoknowbetterthedifferenceofthesate ‘Ofthemanwhofeasleepandofhimwhowakes;{ndnone,perheps,knowthislessthanthelearned,‘whichmustrarelybe'amatterofsomesurpriseqh ter of ih Sonuary,1781. LETTER XcvIl. TheFaculty Reminiscence, Memory, Tate, Sigh ondCompo Hats Yorarbythiimegenabethatobjectbyact-togspanaraeocsexciteinthesolenanions fromiwhich weJodgethattheyreallyexietout‘bn‘Thoughtheimpressions whichOccasionthewe‘ennations aremadeinthebrain,theypresent,then,{5hoaampecienofimagesimiftheobject ‘hichthesoalperecives,andwhichicalledthe Jenrleides,becauseitisexcitedbythesenses. ‘Thos,onsetingadogthesoulacquirestheideaofit;'abditisbymeansofthesensesthatthe:pou!comestotheknowledge ofexternalobject,and fcqures sensible.ideasofthem,whicharethe foundationofallourattainmentsinKnowledge. hiefacultyofthewoulbywhichitacquiresthenowledgeofexternalthing,isdenominated the facltyofperception, 20doubt,on. SondrfaioswietheCreatorhaetl Dotweenthesou!andthebrain.Nowthesoulhas SEiTanthereelthtofrecaingWearsey ‘communicated bythesensop;andthisfaculty SStnedremincence, Oromagbtin. Thu,beviog snscrureovrusceiras, 88 ancesmnanslept,onwlbeabeteast fheideaofthatanimal,hough itjsnolongerbefore Peete hearer rage attenSoh panaeg roarpe ceeaotocedae rmee i ery etes ‘Didbelosetheideasofobjectsassoonasthey oe eee een te enSenabteamomeconeswetesereeee erie nit pean a see Sere at earn comma te cedingideasbeing‘extinguished, asifwehadneverPortin,therefore, afaculty essential toreasonable welts Maret uly coment rewgmae Rectal Seneca” Yahane ioe ee role raemeans follows, however, thatwehaveialways in ae tate Mesa Ho hee me owe orca lo ratem Memes Sey ae eaten yea eeculet sweforgetthementirely; batfrthemostpartonlype ifyoushould happen. forexample, toforget the demonstration ofthe Pythagorean theorem, with ‘ie ce php Tool naSets anpomforePaar,fonnoninteoPond meee eent EEa aate i snmagntrotnymonte, you $l ree rset andthncn n onea a eesC0lleanyome Sepyaya Slyeingaeltl reeeanteetre aeeserefre cartly dings batwooneT eaas= 396 YACULTYOFFRRORITING. , representedtousbythesenses;butweourselves {Bhrecoloctoddetonhemade!oheses, tsfarasworememberthem. ‘Thedoctrineofideasisofthelastimportancefor thepurposeofathoroughdisquisition oftherealsources ofhumanknowlege “And;ot,ideasare ingint complce.."A simpleiain whichtheeeseeing &toae ‘inguiah,andremarksnopartsdiferentfromeact ‘other.Suchis,forexample,theideaofasmell,ot Ofaspotonasubstanceofonecolour;suchislike-wise thatofastar, inwhich weperceive only one Taminous point." A’complex idea isarepresentation{inwhichthesoulisabletodistinguish severaldiffer-‘entthings. “When, forinstance, welook attentively‘atthemoon,wediscoverseveralJarkspots,sur-Tounded by‘contours more Iuminous; weremark ieeround,gure ‘whenbeifullandher hornedfigurewhenwaxingorwaning."Onviewing hherthroughthetelescope, therearemanyotherpar teulars distinguishable, eee beholdngtRoepaleoffogarden?"When ‘notOFafinegarden?When YondotekeHourtoeaihter,youwilinitthediflerent traitsofthecharacters, hichyoucanwitheavedistinguish romeach ‘ther. “This, then, isacomplex idea,asitcontains &variety ofsimple ideas. Not only. this Letter, taken inwhole, presents acomplex idea, from itsonaiting ofaplurality ofwords buteveryword tooisacomplex idea, being composed ofseveralcharacters: nay,everycharacterisone,tromtheStogalarty oftheormwhichitoguahes itfrom ‘thers;buttheelementsorpointswhichconstitute fverycharacter maybeconaidered assimple ideas, inasmuch asyou n0longer perceive inthem any diversity. "Agreater degree ofattention willLike- ‘wise discover. some variety iothese eleweuts,oa ‘viewing them through amicroscope, prot ormT mera ay cate sege {ngithe diferent partsofanobject. Aclownand Division ofIdeasintoclearandobscure, distinct and setalionmadetytheseanheetsicJoochre;butthemoreattentionthatweemploy _ y 338 DIVEMON OFDRAB, Itisfurther nece ‘that therepresentationin thebrain should bewell expressed, andcontain theSuratmecalcres mrss Siepeaoucaraae sehitksict psutepaeceva cama,tie iconlaertoniasSaESrubae Pact ay bet ietha aotitecarly ieSoeray sacle pamelaigete Seahinertia fatmatconn SereLeeefoents Beatahee ‘ EC yen ites a feetnaedi seagate er,mre Sere aahaarrtantke Terie astaacvarbeySe saree ae eects meat tate aeae SicecicsadyachesSotivokl eteES ane wey pn eler ohoat ageAen es rcaSe ee are, occa iT ea eine ete Perio eernaerdserene ayia a feey eee ereSe iene Geags Satcrreny aemisoe Serratia ia{2,0spesdilyacquired,thatevenachild,ater& ttle application, can read with astonishing quick- piviniow oFeas, "929 en.Toratingapieceofwring,wemasthave avery distinct idea ofevery charatier; thus alte tion Jesusceptible ofavery high degree ofperfec. 2 ee sywilpod ithwhatamazingrapiditywillaprodcientin musicexecute themostdificult piecesthough. he never saw itbefore! Itiscertain that hisattention ust have run over allthenote, one after another, andthat heremarked thesignification ofeach, His Mtention, however, isnotconfined onlyto’these Roten;itpresides kee overthemoonofthe Ingers,notoneofwhich‘movesbutbyanex trierofthesoul;heremarkslkowie,attheee time,howtheotherperformers execute theirparts, vin, uponthe whole, altogether surprising towhataheightthealdress oftiehuman’ mindmaybe ‘carried byapplication andexercise. Show thesamme piece ofmusie toabeginner; howmuch timedoes Ferequitetoimpressonhismindthesiguifeation ofeverynote,andtogivehimacompleteideaof &‘whiletheiuaster acquires itbyalmost asingle “This ability extends equally toallother kinds of cnjet, "inwhichoneshanaytly sures Enbthet. There are persons who, withoneglance Be’peron patsng Delvehem,aurea distinctidea;notonlyofalthefeaturesoftheface, buttheparticulars ofhiswhole dress, dowh tothe minutes trifles, while others areincapable ofre- makinghemostkingereumstances, ‘We observe, inthis respect,aninfitediference amongmen.‘Somepromptly catchallthediferent marks ofanobject, and form tothemselves adistinet eaofwhihatformed byothers extremely ‘obscure, "This dilference depends, notonlyonmen penetration,butlikewise onthenatureoftheobjects. Rinusician catches atoncethewholepleceofmusie, andacquires adistinc! ideaofitybutpresent him stn aieeeofwritinginChinesecharternd 990 aseraucrion oFnoonbowilhaveonlyveryobscureideasindeedofsuchtring:theChicasonthecontrary,wilknowstEeepairealportofacySaracenbat will,inhisturn,understandnothingofmusicalnotes. FheGoinsnervein4aotwcheever tabeforeathoosandpatioswhichescapethe ‘Matonofthertherchectdar,by Singleance,inabuilding,manythings other, Fi much gresledegreeofstention, ouldnotevedacoroseds itialwaysnettoformdistinctideasofthe ‘objectspresentedtooursenses;inotherwords,to feank lltheparteofwhichiheyarecomposed, od the matke which divnguish ahd characreras ‘them.jFromthereobservations youwilleaslycom- preheodtheuviionofcustoobecursandSeer, {Etoconfusedanddistinct"Themoredistinctthey ae,themoretheycontributetotheadvancement of knowledge.32February,1761. LETTERC. heABatractioofNotion,Notionsgeneralond OeMette”OfGomesendSpeed ‘Tux senses represent objects only which existsternlyandsenateideasllrtetothemsat oftheee sensible ideas the woul forms toieelf fare‘fotherMeywichwindedesived from>,butwhichnolongerrepresentobjects maleicngoramlookatthefallmon,and feyenonnyoentformtan ofyovnness, butYcaanotafr’thatfoundaoes‘existsofitself. Themoonisround,buttheroundfiguredoesnotexitseparatelyoutoftheoonIk‘isthesamewithrespect toallotherfigures;and ABSTRACTION OFNOTIONS. sar trhenTweeatriangular,oraguaretable,mayhareIeMlonfewml ofeons, srkgurenthswtoar partyfomEm sbject possess er"Theideasofnumbershavethesameorigin.Har- ingseenfroortreperson,thesoulformsthe 12Stoortnewihout ataching itanyger tetheperene Having ready acquired foe ofthree,thesoulisabletoproceed,andtoformthe easofgreaternumbers,ofToor,oyten,ahundred,1ihousad,andsoomwithouteverhavingprecisely teen aomany things together. "Asingle tnsanes, therefore inwhich wefave aven two orthe OF ects, may carry the. soul forward tothe forma: iinrt ieofeinermane, betheyevrvoCSPsamethingoltoBrenandyouhave thopower offorming 19youse theidea 3a ply. oyithHeseyorzap hough youeverffaveseenanobjectofthatform,andthoughnoonesuch, perhaps, ever existe.erethesollexertsanewfacalty,whichiscalled ‘the power ofabstruction; this takes place when the ‘soul fixes itsattention ononly:ginequantity‘orquality ‘oftheobjectandconsidersitseparately,anif SteenlongerattachedfoheejectWe,for InstanceIptmyhandonsheatedstoneandone finemyattention totheheatony,Iform(romit theeyo heatwhichis molngattachedtofe Bone"hpenobeatinotebyattractionag it'spartedfromthetone;andthesoulmight favedened thesame idea fom toucting&piece Wod nates orByunin tehandatBot ‘Thon, bymeans ofabstraction, thesoul forms ashcardlneasoftequaatesadpropericnofobject, byseparating them afterward from tneshjecistromgelvees asvtrhenLseesredcoat,and{myattentiononyoathecolourformtedes 382 ansrmacrion oF NorIoxs. ‘ofred,separatefromthecost;anditisobviousthat ‘red flower, orany other substance ofthat colour,‘would haveenabled metoformthesameidea."Theseideas,acquiredbyabstraction, aredenomi-nated novons, {0distinguish them from sensible ideas, whichrepresent toveobecs rellyexisting,einalleged thatthepowerofabstractionfapre; rogaiveofme,andofserrational Beings, and thatthebeastsareentirelydestituteof.Abeast nnyexperiencethesamesenmtionofhotwaterthat wwedo,butisunabletoseparatetheideaofheatand Thatofthewateritself:itknowsheatonlyins0far anitisconnected with thewater, but has notthetetraidvaofheatwhichwehave.Itssaidthat‘these notions are_ general heas, which extend to ‘several things atonce, aswemay find heat instone, ‘wood, water, orany other body; butour idea ofheatisnotattachedtoanyonebody;forifmyidea ‘ofhentwereattached toacertain stone,whichfret Supplied mewith that idea,1couldnotafirmthat ‘wood orother bodies were hot. ‘Hence itisevident,Thatthesenotions,orgeneralideas,arenotettachedtocertainobjects,assensibleideasare,andastheyinguin anfomthebracreation, theyrap. erly exalt him toadegree ofrationality wholly Ungusinable bythebeast, “There isstil fartheraspeciesofnotions,likewise formedbyabstraction, whichsupplythesoulwith themost Important subjects onwhich to-employ ite Romere: thewearetheideasofgenusfdoecier mlsee a pear-tree, a cherry-tree,anapple-tree, anvonk, fy ailtheeeasareferent f nevertheless remark inthem several things which they have incommon; asthe trunk, the branches,andtheroots;Totopshoronlyatthodethingswhic thediferentideashaveincommon,andtheobject IR'ehich allsuchqualies meetTclree.‘Than the idea oftree which Ihave formed inthis mannern'ageneralnotion,andcomprehends thesensible ABSTRACTIONOFNOTIONS. 333 Seasofthepear-treotheapple-tre,and,ingeneraleverytreethatextn,Pen Now, thetree which corresponds tomy idea oftreonowhereexiala;itismotthepeattre,for thentheapplowouldnotbecomprehended underiforthsareFesonitanottecherytoenor the plam, nor the oak, de. inaword, itexis ‘only’ inmysool; itis only anidea, but'whih is‘eastianini!mamboeject,”Inke manner,whenIspeakof& iltooisa feneranotion,whichcomprehends athecherry:Ththsfotpteteto Eaterebereytroewouldbe’eld 7‘With respect togeneral nations, every existing ‘object, comprehended under one, isdenominated an_ sda thgeneral ded,saythatofthe rie,idonor orgs.‘These frowords‘ignearythesame tapbutgenon In'themorecomprehensive, includingintavanety fofepocion. ‘Thus thenot of tree may becox steedaronusaicadeshendonsofpear frees, appe-trees, oaks, fis, and 60.on, which arefect,andof9mayoer,achowhichon. {ins agreat numberof existing individuals."Thismannerofforminggeneraleasi,therefore, Likewise.performodbyaintraction®anditiyhere chielythatthesoulexertstheactivityandperforme {hooperations from which allourknowledge isdex Hed. Without these general notions, weshoud ‘fer nothing from thebrates.TehFebruary,178. 4 or tanovase. : LETTER cl. iteNature, Advantages, andNecessity, engagesiNee,AdmndNec CultoctionofKnowledge. ‘Weareven apitode aman may have toexercise thapowerot surat andefuiah bat wiheraliden,hecanmakenoconsiderable progress ‘Fithouttheaidoflanguage,spoken.orwriten, swordswhichareonlyceriasigecorresporsting swords,whichareonlycerasigue© {oourideas,andwhosesigitestion iesetiledby fustom,orthetacitconsentofseveretwholve "Iwouldappearfromthi,thattheonlypurpose oflanguagetomankind ismatullytocommuntcate their sentiments, and that 2solitary man might €0verywellwithoutit;butalilleredectiononlyis UFiangedge, ceouchtopursuetodcitratetote digi.Sek SpeemsamsOe ‘Toprovethis,Lremark,fratthatwehavescarcely aordtaaylnguage’ haesiuieation ia {achedtooneodivduaobject.Ifeachcherry-treo ina whole country had ilaproper name,oswel everypenr-tree, ind,ingenera, every.indvidoal fre]whatantoursComplication inlanguage ‘wouldresultfomit!Were:{underthenecessity OFrpoyingparticletertdenoteveyaoe Oferin myBares,orfhou omcares fhink'6t togive each »particular name, this beaeuneleestomyselfetoother.ithe, eryimperct eerton ofte, azungefosaythatmenhave,fromthefst,impowed Shallindividual objects certain namesto servethem | or tasacios. 308 forsiqns,‘Thewordsofalanguageexpressgeneralnotionn;andyouwilrately‘fadovewhiehmarks ‘nlyatingleindivgual. ‘ThenameAleonderthe ret iapplicable 10one particular persons, but ‘Son ite somponnd name.” There try nave boca tany thousandsofAlexanders,andtheopinegreat xtchdsToaninfitenumberofthings”Itaas that allmen bear names,todistinguishthenfrom others though these names maybeTrequentlycom. ‘monomany."Phe eavence ofalanguage consists rater inite containing words fodente general notions aythat oftree corresponds tox profigiows numberof indi ‘dual beingn "These worea serve notonly 40conveytoothers,whounderstandthesumeRnguage,TEsame iden which Iafix tothe words: butthey trelikewise reat sutstance omen represent {isiea tompecie, Wihow theword tree whice Fepresets tome thegeneral notion oftee, ImusTilgivetomel!onceaeherry-tree, apent treet anappletree, fy ey and thence extractiyoflan's ama” ia Tanly opyresethemind,andspeedilyinvolvetin theresent perleniy.” ‘Buthaving,onceforaldetermined toexpress bythetermtreethegeneral Retinformed Oyracing emawaye ekShee imyaoa Yoeene notion, without my Baring Sceasiontecollect tsorigins andsceordgly, the Sword tree alone, forthe moat par, conetttee theertievoawiholtherepent ofanyfel tre. ‘Theword maniyinlkemanne, asigntodenote thegeneral notion ofwhat allmen have facommons n't would bevery diet wotellorto make the meronofathanconanWools raythatheioalvingtwoeqedein Zoekwouldikewivebeinkidedinthisdesertion,Would yousayin words ofPlato's defiton thaieis'aiwolegged saimalwithowfeathers?”You _~ 7 338 ortanovace.‘haveonlytostipthecockofhisfeathers,inordertobatthePistonman.donotknowwhetherthosewhosaythatmanis amanimalendowedwithreason,expressthemselves,moreaccurately; forhowoftendowetakeformencertainbingofwhoserationalitywehaveos. surance.Onviewinganarmy,Ihavenottheleast Soobtthateverysoldierieamen,thoughIhavenot thesmallestproofthattheyaroallendowedwithreason.IfIweretomakeanenumerationofall themembersnecessarytoconstitutea™man,some tienwouldalwaysbefounddefectiveinon,per tapeinsoyeraofthese,orwemightfadsomobeat ‘whohadthemall."On'investigating, therefore,theoriginofthegeneralnotionofman,itisalmostIpomletosywherein cont (0one,however,hasanydoubtrespectingthesig-Rifeation‘f theword;becaueeveryone,wishing toexcitethisnotioninhissoul,hasonly’tothiontewordmenifbewri onpape orheardi ,according’astherespectiveHagueofanySemaybe.fencewesethat,forthemostpart,theobjects ofourthoughtsarenotsomuchthethings selves,anthewordsbywhichthesothingsarede- notedin +whichgreatlyfecilitatestheex- exciseofthought.Whatfdea,infact,doweasoo- intewiththetermsvirtue,liberty,goodness,dc. Notsurelyasensibleimage;butthesont,har fenceformedthesbrractfotionswishcorrespond ‘bonght,npceoftethingwhichtheydnote, ings which 8Tyhayeee ea itwannecessarytomake,inorder{oarriveatthe Feconilredstheywerethentobecomparedwit ‘considered;theywere thedutiesimposedonthem;inconsequenceofthis, ‘wogivethetameofvirtuetothedisposition which‘timdnhastoregulatehisactions tohie runrretions of 4taxatack. 337 ‘duties. But,onhearing thewordvirtuerapidly|foundinconvereation, doweswaysconnectwith{itthiscomplex notion! Andwhatideaisexcited{nthemindonhearingtheparticleandOralsoprosnounced’ tisreadilyseenthatthesewordsimportepecies ofconnexion; bottake what pains youlensetodescribethisconnexion,youwilindyourekeif under thenecessity ofemploying other words,hone siguieation itwouldbeeqoaly difieule t6 Explain; andifIwere Yoattempt anexplanation of theimport ofthe particle ond, Imost make frequent tseofthat very particle ‘Youarenowenabledtojudgeofwhat‘Sdrantagecaepegeageweshouldhardlybein'tcondition to ‘we a in‘ condition to‘thinkatall. 7 10h February, 1701. LETTER CH. OfthePerfectons of@ Judgments andMianofPropelion forceOXmogteeealparler ' 1nave been endeavouringtoshowyouhowneces. sarylanguage istoman,otonlyforthemotonimunfeaton ofsentimentandthought,butlike: writefortheimprovement ofthemindandtheex: tensionofknowlodge."Thesesignsorwordarepresent,then,general tions,oachofwhichisapplicabletoaninfiniteum. borofobjects”as,forinstance,theideaofhot,and ofheat, toevery individual object which ishot; andtheideaorgeneralnotionoftreeapplicabletoterydalreeinagardenoroeswhether hervies, peas, oaks, orre,de. ‘Hence You tust besensible how one languagesmaybeoreperfectanabotber."Alanguageou 13 38 (OFTHEPERFECTIONS alwaysisv0in tionasitisinacondition to expromapreternumberofgeneralnotions,formed {Batweamtsatiatetheperfectionfslanguage, ‘wemust estimal mnofa Formerly, there wae noword intheRussian lan- guagetoexpresswhatwecalljustice,This‘wasSertainly avery great defect, asthe idea ofjusticeisofverygreatimportance inagreatnumberofourJudgmentandreasonings, andaviisecarcelypos- abletothinkofthethingitselfwithoutatermex:Prossive oft. They have accordingly supplied this Eefect byintroducing into that language aword ‘which conveys thenotion ofjustice. ‘Thesegeneral notions, formedbyabstraction, arethesource ofallourjudgments andofallourreasonings.Ajudgmentisnothingelebuttheafirms-ton, ornegation, that notion isapplicable, orin- applicable; andwhen such judgment isexpressedit'word,wecaliapropio." "Togiveanox ample: Allmen are moria,inaproposition which fontaine two notions; the frst; that ofmen infeneraland thsecond,tatofmoni,which Eomprehends whalever ismortal. "The judgmentSonatapronouncingtaming(AtieRtn ofmortalityisoppicabletoallmen.Thisinajudg-‘ent,andbeingexpressedinwords,iina tion;andbeeatee fans,wecaltaxaprmateeroontin: TEAdenied,wowoulcllitnegate, Tach as this,Nomanisrighieous..Thesetwopropo: titions, which Ihave introduced a8examples, tre‘eunersl,becausetheonealfaofallhenthat‘theyaremortal, andtheotherdeniesthattheyare"torearelikewiseprtalarpopotins, both reareLikewise i Regativeandaffirmative;a8Somemenarelearned, ‘Somemenarenotwise.Whatishereaffirmed, ‘anddenied,isnotapplicabletoallmen,buttosome ofthem. Hencewederive fourspecies ofpropositions. or ALanovAos. 339 ‘Thefetinthatofefrmatinanduniversalpropon-‘Hons,formofwhichingeverali:rn 2.rropntos hfofwhichipera ‘The third isthat ofaffirmative propositions, but porticatar, contained inthis form: ‘Andnal,tefourththatofnepativeand ,foally,whefourththatofnega tiadarpropotions, ofwhichtheforma SomeAisnotB. Althesepropositionscontainessentiallytwono- tions,Aand'B,whichareclledthetermsofheprop- fonthe,fratofwhichairsoretnoe whichwesayisapplicable, oFinapplicable, tothe Frat isthe attabute Thus, ntheproposiion, all men aremortal, theword man, ormen, isthesubject, nd the word mortal the atirbute these words are ‘uch used inlog, which teaches the rles ofjust *Tiesefourpecienofpropositionsmaylikewise berepresentedbyigures,soaytoexhibitthelrnature {otheeyeTats! bares snnane towards‘comprehending moredistinctlywhereinheaccuracy Sofachain ofreasoning consitn ‘Awageneral notioncontains aninfnite number ofindividual objects, wemayconsider itasaspace fmwhich they arallcontained. “Thus, for'the notion afman weform aspace, Fig. 41. Pig Aiyin which weconceive allmen tobe comprehended. For the ‘notion Ofmortal" weform anotherPig.4,in swhich weconceive every thing mortal {0becomprehended." Aad when|afFig.49. frm llmen ere moril itinthe same {hing with afirming that theSet Ggure Iscontained inthe second. 0 OF sYLLoouxE. 1.Hageitohatherepenntation of tinaltral poping inwitchtespaceA.Se.43,which ornate er teaSCRattainhegtacs wTAtosoetveuiera open onietncspaces kindBatwmich yy Aalways:thesubject,undBoFig.44. ‘theatersbute, willberepresentedthus, Tetneepeetours other; becausewesaynoAisB,or ifncmpeteddneonAinathestem ptepopeFggourmet Eraaes risoajreeneliece9, Atostr brata| Speke hsioneho TW"Formrtpreropa tions,as,some.isnotB,apartoftheFig.46.Mnfgrereebope’(lf) irece ne! siccooper aich MthFebruary,1761. ‘Byllogisms,andtheirdifferentForms,whenthefirst or Proposition isuniversal, ‘Tuesecircles,orratherthesespaces,foritisof gelapeance atueote Stalsoe anf gS ienat or exizoctas, au toexplain; whereas bymeans ofthese signs thewhole isrendered sensible totheeye.Wemay. Trnploytn;epacestovmed atleeforepress everygenera‘notion,andmarkthesubjectofa.Bitebyanotherwhichcontnins8."Thenature.of thopropionic senys nora eer tat betpaceofAinwhollycontainedintheapaceor thatit'sparlycontained inthatspace’ orthata arta eta ouofthesce BYonaay shat Bheapuce A wboly oof Bt See?Sakae9ahereoroLacie teemt ©)() COs)G0») ry rastrerd rs7 us oFsvutocus.‘Thetwolastcases,which particularinsseentocontainaowtaiinDt Eoswhertbagetperofwhici +contained,ornotcinB.Itisevenpossi Bieinthecaeofparticularpropoition,thtthe notionA'maycontainthenotion8en- rely,asinFig.47;andthat,attheFig.47, seretimeitlearfromthe,gure,& ofthespaceAmaybeinthespace BaadhateprtofAtaynotbefnBy Now,ifAwets,forexample,theideaof freeingeneral,andBthatofoak,which incontsined whollyintheiretthefollowingpropo-sitionsmightbeformed:1.Alloaksaretrees. II, Some trees are oaks. attemall,Someeeeaenotaka, fomanner,ifoftwospacesoneisent cfthetherainFigAicnanwellay ‘AisB,a3noBisA;anil1weretosaypomanis‘tree,and'notreeisaman,Ireedcinwheriefronotionsare8 in3 itmay PartincommomgotAaB If, SomeBisA. AIL SomeAisnotB.miIV.SomeBisnotA. ismaysufficetoshowyouhowallpropositions sayberepresentedbySiguren;buttirgroatnt lyenotin reasons which,fen,Becojectlatodrawtigcancinromcertain given propositions. Thismethod will discover-to1sthetrueformsofallsyliogisms.‘Letusbeginbyanaffirmative universalproposi- tion:BreryAisByFg.43,wherethespaceAie ‘whollyinthespaceByandletusseehowathird ‘otionCmustbereferredtoeachoftheothertwonotionsAandB,inordertodrawafairconclusion,isevidentinthefollawingcases, monn ineinthenotionB,Fig48;hencere- /“-% ayesoe LOE cm, ce ct soe nari ee == hasapartcontainedFe. Fe: sea ree wiecoeneta OR? wane nse Renea BGBnet eaonctaifte dae Me OFsYLLootaMs. IIL.ButifnotionCwerewhollyoutofnotionB, 1kwouldlikewisebewhollyoutofnotionA,aeweBTCAhcl enoye“= EveryAisB: NeeRe Reta re RSA alitonA,bocausethislastiswholly Ye) inthe‘notion B(Fig. 64). Hence ma a it» ooo ee CE YEE SI he ga whole ofnotion B,part ofnotion C will certainly fallinto notion A(Fig. © Shona ee aie ‘thefirstpropositirn isaffirmative anduniversal. Let usnow suppose the first proposition tobe negative anduniversal; namely, ohavaeeratiy SharamsHaRe comet TTeRSe vie meee ckHie Geemtecy utofnotionA(Fig88).Hence ® Rey™ ioAisB: ButEveryCisB: meniBEE o srLt0ctws. us HL IfnotionCisentirelycom.Fig.87. probended innotonAriemust NC Niobe nll excided omution(ig5),."Hencea ey ® im ofths form:eenhsNo.AisB: ‘Therefore NoCisB TL,IftotionChaspartcontainedinnotionA. thatpart‘mostcertanly’beomtofnotionBsa8 Agds,oniPi.60and0."encewapogims . No Ais B: BatSome Cis-A,orsomeAisC: Therefore Some Cisnot B.Fig.58 Fig.09. |Fig.60. TV, Inlike manner ifnotion Chasapartcone tained inB,thatpartwillcertainly beoutofAa9 feign aloig, and68.Hencetheooon SOR NGAisBY ButSomeCis,orsomeBisC: ‘Therefore Some isnot A. Fig. 61. Fig. @@ CLEFig. €O_—nurrmuxer youme oFsvito3tm. Astotheotherforms,inwhichthefratpropos. tion’ isparticular, alrmative, or negatives shaltBerintother Lesterhowthyayboron190trary, 178, LETTER CIV. Different FormsofSylogizms,whasefeatProposition1Mprtedar. IntheprecedingLetterhavepresentedyouwith sueerentformsofalagims ormproaaoo-Ingo,whichderivethiroriginfromtheBtpropo- sition, when iisuniversalaftrmative, ornegative, Teail remains that laybefore youthose mylla- fim whoee fratproposition isparcular,afftms- tive, ornegative, inordertohave’alposibleforme ofsylogam taeadofr conch,12h eo,theSitpropeiion, aaa and pariclar, beexpressed inthis general form— SomeAisBoerig.49); inwhich‘partofthenotionAiscontainedinthe|Letusintroduce athird notion C,which, being referred tonotion A,will elther be’Contained inHotionA,asInFig.6485,and60;orwillhavea art inthenotow A,asin Pig. 07,68, and 00; oF Will beentirely outofnotion A,aainFig. 20,7 tnd72, "No.conclusion ‘can be’drawn ia’any of these easesaitmightbepossiblefornotion©tobe entirely within notion B,ofa par,ornotatall Fc Fig. 65. Fig. 68. DIFERENT roRxs OFsvitocims. 347 Fig.07. Fig.08, Fig.00, @:)CO 5 Fig.70. Fm. Pen. ButiPnotion Ccontains initself notion A,itisgriin.thatitwiiewie containapartofton BlasinFg.73and74.Hence resultsthisform ofsyllogisns Some AisB: ButEvery AisC: ‘Therefore Some Cis B. Fig. 73. Fig. 74. Itstheanno when wecomparo notionCwithno- tionB:wecandrawnoconclusion unlessnotionG containsnotion Bentirely (Fig. 75and76); for Fig. 7. Fig. 78. inthatcaseasnotionAhaspartcontainedinno-tionB,thesamepartwillthancertainlybecoo- , ‘MS=DEFEREWTYORMSOFSYLLOOMES. ‘tainedlikewiseinC.Henceweobtainthisform ofsyllogiem :SomeAisB: a s ‘ofnotionAisoutofnotionB. GB) aeaetmaoe semoiertanar wasnTal mae ateButEveryAisC:nando Tag erie isTkowineeottaisybeoutof©(Fp.50andt-pl a) ‘Hencethisformof syllogism:ns, ‘ThereforeSomeAisnotC. Itmaybeofuretocollectaltheeformsofet Jogismintoonetable,inordertoconsider themats‘singleglance. DIFFERENT FoRMS oF sYLioowms, 349 LEveryAisB:XI. NoAisB:ButEveryCisA:|"ButSomeCisB: ‘ThereforeEveryCinB.|ThereforeSomeCisnotA. iLEveyAB: Xi,NoAwB:But Some CisA But Some Bis ©:‘Therefore SomeCisB.|ThereforeSomeCisnotAeU,_ EveryAisB:|XIIL SomeAisB: ButNoCisB ButEveryAinC: ‘Therefore NoCis A. [Therefore Some CisB. iv. Every AlsBXIV. Some Ais B:ButNoBisC: ButEveryBisC: ‘Therefore No Cis A. [Therefore Some Cis A. V.EveryAisB:|XV._—SomeAisnotB:ButSomeCisnotB| "ButEveryAisC: ‘Theroore SomeCisnotA.[ThereforeSomeCisnotB. VE Every Ais BJXVI_— Some ignotB: ButEvery BisC:|ButEveryCisB: ‘Therefore Some Cis A. [Therefore SomeAisnetC. Vi. NoAisB: (XVII. Every AisB: But Every CisA)"ButSomeAisC: ‘ThereforeNoCisB,[ThereforeSomeCisB. ‘Vill NoAisB: [xviii NoAisB: ButEveryCisBut veryAisC:‘Therefore NoCisA.|ThereforeSomeCisnotBe IX NoAisB; |IX. NoAisB:ButSomeCisA.ButEveryBisC: ‘Therefore SomeCinnotB.|ThereforeSomeCisnotA X—NoAisB: (XX. EveryAisB But SomeAisC: ButEveryAisC: ‘ThereforeSomeCisnotB.|ThereforeSomeCisB. Vou. LG g 50 anim ofsome rises Ofthese twenty formsIremark, thatXVI.isthe ooherons fo roma atXVih ‘ifyouwriteCforA,andAforC,andbeginwith rocaci ite See ‘two principles, respecting thenature ofcontaining pee i gem! meaTL.Whateverisoutthecontainingmustlikewise Be reetiad SOME ee ence al Ee aecw pron tandthethird theconclusion. Now, theadvantageoieweomefireontaon Ben ony meted ofdecoveringantetageonypedofacreing Sara aria aw ar hee‘andtheothertheminor. majorPs LETTER CV. Analysis ofsome Syllogiams,teyoureptstetonafra A7aeeet loitiarenone7mpasnae citer ayorzo omy en 0VINTUOUSMAN18ASLANDERERButsowsStANDERERS ARELEARNED MEN: thinghollewithpegandtsaltheotherswhieh gueliicope aloe cut Brlevel eate aie “hatiseBvruous men,thatofslandcrerand 78% thatofearnednen. the ®siete mt SiGeminder omer! @ Fis wainthewoodpe 2°tion,thatsome mencomprehended in therefore, some part ofspace CisinB, Va 292° axatym Opsox eviiocmes. ‘ndthatthewholespaceBisoutofspaceA,itisevidentIRNTheeaeprtopce€mahee inebeoutofspaceA,thatis,omelearnedmenare ot virtuous,“Itmustbecarefullyremarked,thatthisconclu.sion respects only the part *ofhotion C,which ie comprehended innotionByforastotherestitis Uncertain whether itbe likewise excluded from notion A,asinFig. 85,oFwholly contained ini,asinFig.8,oronlyinpart,asinFig.87.Fig.85.Fig.86. Fig.87. Now,thisbeingTetuncertain, theremainder otspace€fallsnolatallunder‘consideration; theeaclsion inimitedtothatonlywhichiscertain, hatistosay,thesamepartofspaceCcontain inspaceBiscertainlyoutofspaceA,forthislast "TheJistnesofltheotherformofsyogjustnessofalltheotherformsofsyllogism aaybedemonstrated inikemanner:bualose ‘which deviate from thenineteen forms laid down, orwhich are notcomprehended under them are elite offoundation, anleadtoerorandfalse.‘Youwillclearlydiscernthefaultofsuch3lo. gism,byanexample,notreducibletoanyofthe Rineteen forms: There Ronmee wee:(oresoMeVIRTUOUS MENARENOTLEARNED. "This third proposition may perhapsbetree,bat {itdoesnotfollowfromthepremises.THEYtoo(Che premises) may very well botrue, andinthe‘resentinstancetheyactuallyare00:butthethird ANALYSIS OF SOME sYLLooIMS. 358 4not, forthat, afairconclusion;becauseitiscon trary tothenature ofjust syllogism, inwhich the conclusion always mastbetuewhenthepremisesfare0. Accordingly, thefault oftheform aboveproposedisimmediately discovered, bycastingyourpehonFig.62"LetgpaceAconanalheleured, ‘pace Balltheavaricious, andspace Callthevita us. Now, thefirst proposition isrepresented byig. inwhichpa=ofspace’A(helearned)iscontained inspaceB(theavaricious) ;butitby tnomeans follows, Fig. 89,that partofspaceCmust beoutofspace A Fig. 88. Fig. 89, Itievenpone forspaceCtobeentity within space Ay'xs inFig.60,orentirely outofi asinFig. 01,andatthesame time entirelyoutof spaceB. Fg.90. Fig.01, ‘Asyllogism ofthisform, accordingly, istotally false and absurd ‘Another example will putthematter beyond a doubt: sows TEES ARE o4n3: ButxooneiAri: ‘ThereforesowerineanenorTREES, ‘Thisforaispreciselythesamewiththeproced Gi 354 Dorrexext neonts1x0{ng,andthefalachoodoftheconclusioniamanifest though thepremises areundoubtedly true.‘Butwheneverasyllogismisreducibletooneoftheabove nineteen forms, you maybeassuredthat ifthetrepremise aretithe conclusion unges-Honablearaysis oto, "Tienceyouperceive how,from certain kaown truths, youattain others before |‘unknown; andthatallthefeasonings bywhichweSemonstrate somanytrisIn maybe| reduced toformal syllogisms. Itisnotnecessary, However, thtorrasonings shoulalwaysbepro- posedinthesyllogisticform,providedthefondaIreatalprincigea tthesame. "Inconversation, iiscouseandinwong,werathermake8point avoidingTmontfartherremark,thatasthetruthofthe remissbringsforwardhatoftheconclsion, it Joesnotthenee necesearily follow, that when ‘one ‘orboth ofthe. premises are false, the conclusion‘ustbeoolikewise;butiticertain,thatwhenthe Conclusion isfalse, one ofthe premises, orboth, Absolutely must bo’false; forifthey were true, it ‘wouldbeimpossiblethattheconclusionshouldbe fase.Thavestillsomefurtherreflectionstoeub- ritfoyouotiswubjctwhichithefoundation 38Gertaityofalltheknowledgeweacquire ihFebuary, 178. LETTERCVI. { Different Figures andModes ofSyllogioms. ‘Tur reflections which Ihave still tomake onthe subject ofsyllogism maybereduced tothefollow: | ingails ; |"Asyllogistacontainsonlythreenotions,named|terms,it8fara8theyarerepresentedbywords. Forthoughasyllogismcontainsthreepropasitian~ | ovesorsrusomen,=6 fsckpoytinorit beconsidered that each term istwice employed in. Pescehenbrand Thethreenotionsare‘markedbyrelettaneA,B,C, whicharethethreetermsofthis iam;TESLA Weetheaeh tFn eeeee FTP ee aan carwfly Alig ihre thse spmocerme laean:_Teo ofth,mane sory orem Aus fume bah one, oe ee cen oe tece eaethegz orAcetteao Fren: oeroe eatsweae [ ‘Thenotion/earned istheminorterm,thatofvirsncetrentmayemoocaeEetnonteroftheproposon,ia asicsfisrirofSoPisoni. tsastaresieop ees Rein ery ties rand, connieLonicaterrei \BeagenoveSoerer pTcar ste meester hemaetmsaaoaee 356 ‘DIFFERENT FIOURES AND Thnerdrp emiemir trothesubjectoftheconclusion;andhenceithasthename thos jerpptofasyllogismconta oninofayllopiemcontain themeanterm,withthemajortermsorpredicate otheConclusion; andtheminorpropositioncontaing jemean term, withthe minor datasorsulject ol ‘NiveSyllogaimsaredistinguished underdierentcasheeerdingasthe.meanrmoccopesthe Meer rie Std intheproms Togicane hive eotablstd fo fgures ofeyo~ sine hich aretht defined "Tusfretguehatawhichthemeanterm tueetject major proponiton, andthe prea tale inte mor.hesendrainwhichthemeantermia thopredicateAfboththejorpropoltonandtheMriiedprhataihthemenerio{hesubjectinthemajorandminorpropositions."TheJourthfigureisthatinwhichthemeanterm isthepredicate inthemajor proposition, and the fajeetin heminor, Lt Pe the minor term,orsubjectofheconclu sion;Qthemajorterm,orpredicate, oftheconcluc ‘sion; and Mthe mean term: the four figures of me willberepresented inthemanner follow- Figure First,‘MajorProposition |M—-—— Q +MMCBrepociton |B= Solana|Poa ‘Figure Second. ‘MajorProposition |Q——-—— MseesFpeciton |ne Contain |P———Q Mooks oF syLioouas. a FigureThird MajorProposition|M-—— KinsRepeatn|th——F Conclusion |P—-—— Q FigureFourth. MajorProposition|Q-———M MinorProposition |xP Condsion |P——Q'V.Againaccordingasthepropositions themelves aroantforel orparlctla ditatie oragate, Esedgureconta several formaeedede ikOrder themoreclery tgrepreent thesemodesofSiehBere,reark.bythoiceaera Stirmativepropositions; bythfeterB,universal Begative propositions; bythe letter J,particular affirmative propositions: and, finally, bythe letter 0;particular negative propositions: orelse, “Areprosents &universal afinaive proposition. Eerecta universal negative propomtionIrepresentspataanativepropoatonrepresentaaparticularnegativeproponiion. VasHenceourhineteen formeofsyllogism abore described stereducible tothe four Bgures which T ‘nave Jot laiddown, an thefollowing tan: 1.ModesoftheFirstFigure Ast Mode 24Mode.Tkwad teempotEveryPisM:| putSomePsMt: ‘ThoreforeEveryPinQ.|Therefore Some PisQ. “wed. | athMode HAE BO. NoMisQ: NoMisQ: BotBveryPieM:|ButSomePiM: ThewfreNOPla@.|ThereforeSonePiot 338 aooesoFsyLtocisus, TL.ModesoftheSecondFigure, 1stMode, 4]94Mode,AE. E. ‘0. 0.EveryQisM. BreryQisM: But NoFisM: ButSomePisnotMt ThereforeNoPieQe\|TheroreSomePinnot 3Mode, “ahMode, EAE Bal 0. NoQis M: NoQisM: ButEveryPisM:|ButSomePiaMz ThereforeNoFin. |ThereforeSomePianot . TULModes ofthe‘Third Figure,stMode, 9Mode.wie TAT.‘everyMing: BomeMisQ: ButEveryMisP:|ButEveryMiePi ‘ThereforeSomePisQ.|ThereforeSomePisQ. 3Mode. “ahMode,Mil. BAO.EveryMisQ.NoMisgs ButSomaMigP:|ButEveryMiPs ‘ThereforeSomePinQ.|ThereforeSoe’?isnodGy ‘thMode, ‘thMode,BL. 0. 0.4.0.Notting: SomeMisnotQ: ButSomeMisP:ButEveryMisP: ‘Tharfore SomePiaotQ.|ThetfoeSame’?ieot@. TV.ModesoftheFourthFigure IstMode, 9Mode, ML oo Ta ow veryQis ‘SomeQisMs BotEveryMisP:]DatEveryMisPi ‘ThereforeSomePisQ.|ThereforeSomePitQ, OBSERVATIONS ON sYLLooINNS. 350 BaMode. 4th Mode. ‘AEE. EA. : EveryQisM: NoQisM: ButNowisP: ButEveryMisP: ‘TherioreNoPieQ.|ThereforeSomePisnotQ. 8th Mode, E10. NoQ isM: But Some MisP: ‘Therefore Some PisnotQ. You see,then, thatthe first figure hasfour modes, fhesecond four, thethird sixthe fourth fives 20 that thewhole ofthese modes together isnineteen beingprecisely thosameformswhich {Raveaboveexplained,andhavejustnowdisposedinthefourfigures. Inother respects thejustness ofeach of {ewe modes hasbeen already demonstrated bytho spaces which Temployedtomarkthenotions."The iydiferenceconstinthisthathereTakeuse ofthelettersP,Q,M,insteadofA,B,C.28h February, 1761, LETTER CVI. Observations ondReflectionsonthedifferentModesof ‘Syllgiom. Imarrax myself that thefollowing reflections vwill contributenotaitetoplacethenatureofsyl- Togisme inaclearerlight.Youmostpaypertcaar Attention 10thespecies ofthepropositions which compose thesyllogisms ofeach ofourfourfigures, {hat isto say, whether they are,1.Universalaffirmative, thesignofwhicheA;of, 8.Universalnegative,thesignofwhichis;of, ” 200 onamnvarioms on Tax 8Particularafirmatvethesgnofwhicha;or,“Particular negative, thesignofwhichis0;antyouwillrealyadmitthefstesyofthefl, SomatreconeTooenanceaebthprominesoggprpponions Logics hveHesseform ths ‘Fromtteonegative propositions noconclusion canbe "Tereasonigevident;forlyingdownPandQ tereazon i evident forasthe fermeoftheconclusionandMasthemea {erm ifboth premises arenogave, teallrmatvon sea ony auGareroyor outotM:itisaccordinglyimposibletocon deythugepectngieconerayoa ‘conformityofthenotionsandQ.Though{knew Koryththeasewereatoaad thatneitherweretheCeleRomane,thiswouldnot fenceinthelenoinforiewheterthe rere Goals oratt, ‘Twonegulive recsaes, Serta onococunion, BodhprentonesroetBOoveinstanceparicw- tapropio hescetiteinopetev portcdar proportions noconchsioncom -pertialar prope ‘Thumforexamplebecausesomelearnedmenarepor somesre len, ponteencethatthewhoarepoctaremalevalen, ortttheyaenot90.Ifyoureflectevesoile tnthenatureofaconsequence, youmustime: latelyperceivethattwo:particular premiseslead {eine sancnion whatever Tit, estherofthepremieisnegtive,theconchae sion too pete agi“This thethirdmdewhich logicprescribes ‘When somethingisdeniedinthepretestsme posabletainanytingintheconclanon we Fran abeolutelydenythereUkewine.‘Thsrule | — poreneernones ovezcenms. 8hseyetetyatheoveofego, vitae atsofrn Baefrietea eadandes Bere ‘Thisisthefourthruleprescribed in‘logic.The eprintpedfs,The fenerifweapea onyofaoienoneofthepromiace, rerosacotapeeinaeofairmie fe nana dsanteainlenethpremaesrefetch conc, opiate haeeSeEeivecaieswateer tara aadBesidesuniversalandparticularpropositions,wipe eneanparide rene RSaeee cohmnaeo dheametELS iontae ingseveral beingsinitself;{risthepropernameofBecame geanterransa! emisraceyes onigtor womebeingscomprehended inthonotion, sageoeconan eeSe Now,saytheseauthors,whenwespeakofonly8 Ertecrete Se omeaereoat mine eal feemay eae _—.~ 262 purrmnrr wopus oFsviioouns. ‘notspeakofallthebeingscomprehended intheno- tion ofthesubject, whereas&universalproposition tpepofawit excep. "Th, when thesubjecthsproposionitenotionofae ehjoctoftinropnahiontnosobaeanmotes,Urisebjectotkennal its extont—its foniaexprosaly reto'someyandSyparcapopotonsare bentilly distinguish from universal, asthey tornayeartofthebeingscomprehendediathelrIbisclealyevident,from{hisromartht« singer mastbeconsideredassnversl annspeckngofanindividualayVirgiyitimno feopeat resis tie notchoftheaie,whichie ‘Virghimeelt,butratheradmitsitinalliteextent;rel propecTonsailotsogoprope cerise‘tons, refollowing 18accordigly 3verygood ” ”-Vouraine 184PHILOSOPHER: ButVouraine 184Poet: - ‘Therefore sot rorra uns ruiuonorusns ‘And itwould befaulty iffhe two premises were Perathilogebelongs0guretanhe syhiog R frstmodooftheformA.AI.‘Theindividualidea ofVoltaire isthe moan iat, which isthemubjecttbothmajorandminor;andthisisthecharacterotigurethi. |Flymugromahatnientehave spoken fepropanitions, which00 Woncuats, teoneehichsatedorGexid, oundprepaniny, logic pcatbespecuaa.oct Psaderenat,°°reerPee [ y rere meron, 8 Mite Pn dD cn odipaptines crate! appara aaa dieSitaa {howewhich{havelidbeforeyou,andwhichareSoatsiond tiefousSgaresaboveexplained. Buthichcontainmorethantwonotions,andrempect- IngwhichotherrulesaretobeobmervedihordertoAedesirconclanonsfromtem. i Se A ew comsonarethoaowhichsrocalled hypotheticaloFeon. See onety omer syavoed,speraoases reahater,‘Nowthesotwo.propositions muttbe.connected OthSt,thattheformercannotbetrue,with uae Grea stn,proach ofpeace, wearewarranted insaying, that,Fisica ataatote ASS i at , . 3060arrererneut raoroaoe. ‘then,withtheaddition ofsomeother zshen,iheinofomeihreecehewntepscwnssatenelorsal'WhonwearoUlharpoeslery Fann4 7 fayacresmeenna 3oefoes salretenaoytcoSylofanewkgybefnrendad AuBOteraD: puane: ‘ThereforeCmD."endFor. 7‘IfAwB,CwaiaeD:Parton heres83tot3 ‘TymeFrouneSystconlsion;andyou+BinDeeTologiogomaatantSeaie: 'TensFor.haem: PottoreTersonsOTED.ndnasFrm.Presi buon:TeeseAB:Taeceethlaclou_Tothexampleuddoced Tisgseanase Teedeas|oademsoueerrearecaROTH,PELORDatenararereer:1runtouady vethatToegustomaynot iiaFreeeeleiieeryPoelhak ‘peacemaybeapproaching. | nvrormneat moresment, 8 1 thf eal ren fee aa re tly hpPett meer eran Seta orcas wa Bead lt a ae ahce aes ana ene "td ana elon fryfallacious ;butthetwopreceding arecertainly good, sarees aerreh ate Sic rete Sir cenit geenTEBEwie; thto eh AEd ‘theother,CwillbeD,theconsequent. Logicpre-ae aati i et ieeeEE et moonTee iw ntteeen ma wc ti eat pe ober asaogna ttata ican etree tera te a ier ta ao was gigs eee reERT REE SLE Aye cae tty ti tneneae,'LButsuchasubstanceisnotbody;aeeetaee 366) razsstonoFsxxerions=~ TLButsuch2substanceisbody5 Thereforeitianctepe‘Butitisenfirelyunnecessary todetainyoulonger"1thMarch,1761. LETTERCIX. OFtheImpression ofBenaationsomtheSoul. Havre endeavouredtounfoldtheof JogiwhoseobjectItiolnydownballsrles forrightreasoning, Imuststilldetainyoualitteee re*fromrealobjects,whichstrikeoursenses;andax farastheyarestruckwithanyobject,«sensationcerresmelng eryexcelinSa,‘Notuy&teSontenrepre9theouiheenofIntnceoatofwysftsofportancetoroma, {hatthsensatiisnotindifferent0thesou,baswaysaccompaniod withsomepleasureordingust,‘ovagreateroflessdegree. ‘hismeas,thoideofanyobjecthesokdoosaoewhet{hefateationbywhichthesolJeagree oF‘agreeablyor inagrocablyaffected,thatinlet;butfttllpre- tacventheidenoftheobjectiteNotthatihe iever or eSirorer Sans cee ‘thepowerofawakening orrecallingtheidomat ‘Thisfacattyofthesoul,bywhichitisemsbledtoropollecdeusonceperceivedicalledreminiewhichcontainsthe‘sourceofemery.oped Ofthepowerofrecallingpastideas,thatofper- on Tae nove 207 ceivingwouldanswerlittleornopurposeifTosteverymomenttherecollectionofiaeasonce Beretawoshoulavaysbeinthewateofnew: infantsthatisinastateofthemoetprofoundguorance. "Reminiscence, then, isthemost. pro-tousitwhichtheCresiorhastoatowedothegoutofman,andereitpitalityshinsintheErigiotaireforbyaneofthefetthe sealrafalinsiotestan Knowledgeptttoughrecollectedi the ideas tou eeecheer een fomthminThis,unttheyarenotcompanied 2theseaationnorwthfecoovictin,hatthe ‘ObjectsreallyexisIfyouhavooncebeen2spec {atorofaconfagration,youcanrecalltheideaofit Iheneveryouwilwithoutimagining,however,that weyngtneyoumaynotavetagesofck& ‘erylongtimeyoumaynothavethoughtofsucha‘onagration, butwithouthavinglostthepowerof recallingtheideafit.Ttthesamewiopelheowswhich swehaveonce.perceived; butitfrequentlyhappensiat welove almost entirely theTecollection, ofi“Stherwords,forgetthem.”Woremark,nevertho-Teas,verygreatéiferencebetweenideasforgoten‘and’ideaswhollyunknown,oFsuchsswehoveri,"WitepeeotefitasoonaThemang object Vialafreshfooursenses,wemach ‘morecanlyexchtheSeeoffyandweFecollectPerfectly,thatitisthesamowhichwohadfore Beton:iewoulnotbethecasehadwoever itisherethematerislsta boastofhavingfoundafont tiextrerelclontheouliothing itia ihewoui cicibalemater,énwhichexerject ‘grocapableofmakingtome / 368 SENSATIONS ONmE sovL. lsebuttheideaoftheobjectsandthataslongatftremains,therecollection ispreserved;butthat ‘weforgetitwhentheimpression istotallyeffaced.‘thisreasoningweresolid,ideasmustnoces-sarilyremainalwaysprosentwithustillwoforgetthomwhenveleas!taltheimpressionwere smwhenweplease:andiftheir werettacel,nowculematereclcatkorm ‘had that impression, onreceivingitafresht itbeverycertainthattheactionofobjects twthescneesProducessomechangeta:thetra, {hischangeiaverydifferentfromtheideawhich iecpctaiced byspdthe,sntimentofpearre or‘aawellasthejudgmentrest 4 ‘hetcifichexusedthirimpression,equally require2beingwhollydiferentfrommatter,anden owedwithqualitiesofquiteadifferentnature. ‘Ouradvancesinknowledgearenotlimitedto ideasperceived: thesameideasrecollected inthe‘memoryformforus,byabstraction, generalideasofthem, which containatonce«gestnumberof Hnaividal ideas;andbowmanyabetractdeusdo ‘weformrespecting thequalitiesandaccidentsof ‘Objectswhichhave'norelationtoanythingcorposeas atasoiEE ‘This,a ors understanding,whichcomprebends but2partofthefacultienof thesoul;theotherpatisnotleesextensive,namely, ‘thewilltndfidety,onwhichdependallourresol: ‘ionsandactions.‘Thereisnothinginthebody. relativetothinqualitybywhichthesoulfreelyde- erminesitselftocertainactions,evenaftermatureGeliberation. It paysregard tomotives, withoutbetngYoreedtowdbattotheirinfluenceand.SEi£0senifoiawelastalsrt itwouldbeasimpossibletoimagine Trithouliberty,atabodywithoutextension.God Rimselfcould’hotdivestaspiritofthisessential PIPINbytiaaccordingly,thatwoareenabledto onion Axo ramnamox oF xvz. 00 solve allthe perplexing questions respecting the‘originofevithepermission ofsinythdtheex.intenceofallthectlamtienbywhichtheworldi»porowed;thergreatandonlysourceinhuman10thMarek,1781. LETTER Cx. OftheOriginandPermissionofEvilsandofSin. ‘Tasoriginandpermissionofevilintheworldis sneesStichlesunallgeeGestyperianal‘heologiann andphilosophers. TobelievethstGod, ‘Being supremely good, should have created this Irovdtntoneooverwbeinodwihwichavacety ‘ofevil appeare socontradictory, that somethomasztuetothenecting @principles,theonesupremelysupremelyor"Thiswan'topton,saerainedby’the ancient heretica ‘Known tahistory bythenameofManicheans; who,seeingnoothetweyofScouting forheoriginofer,woreracedfo iiatemy, Though thequertonbeextremely complicate,hissingerem,thatbertie ‘Tully.sential spirits,dispelsatonce«great fartofthediffculicewhichwouldotherwise6i. ‘surmountable. sauna henGohceed man, aeton topreventsin,hinIbertbeing.suscepti boconstraint. Bi,ababofolitwouldHavebeenbetternott0createsuchandsuchmen,orspirit,who,asGodmusthaveforeseen,wouldabuse irberty,andplungeintosin.Tshoulddeemraterrtfenorponthdco,adtopre- {endteJodo ofthechoicewhichGodmight fave beenafetomakeincreatingsprite;andperhape theplanoftheuniverseTeauiredtheexistenceof 270 owen xo rrtauion oF era hesseuodRetheolyreatette _FUSS tororateesanaeee aeertieswens ee card Saneowed runner, a aeeyehtalnesheas “trihereforesapedooable prov ame ata tion toiassaGlonyeraedSeat Sieigaoummroptaaveryfe Sseisepouche ies rally weieeementeeioe ae cee Se eeeweencecinesreethetcbeakcee oe Teactefl Ae hire ofspiritsorreasonablebeings,oaghttohavebeenre- Faerie BrineOnsicatie Oewel BraeareaeeeeOe,BROaaoeorcontehaotra 2RayoneeorcomerneeetdSee etahoeandtematoefeeSebinpn Sato ayertanlaThc mitreSecures option iasinfantsgod,heeatesing teinnethemogresneaenefoundBlySnir woul Zonyahaere eee"lobe iheey rtoeranin pete d cee ee che wo eavesea rtFea eaneneatrheaBe ro a ee oeintoevil.Religion discovers touslikewise 90many + onIGDN AND PERMISSION oF EVIL. 372 ‘ther means which Godemploys toreclaim usfrom urwanderings thatonthsse,wemayretconfidently assured thatGodhasomiited nothing which could have prevented themalignant explosions of ‘men, aut ofother reasonable beings.‘Bitthosewhobewilderthemselves insuchdoubtsrespecting theoriginandthepermiason ofeiinthe'woriperpetuallyconfoundthecorporealwith thespiritual world; they imagine thatspirits are,as bodihsmcepibls afcnuan Severedine i frequen leof preventing, among thedrenofafamily, thesoldiers ofatsrmy,orthein habitantsofacity,the,apeeruption ofperverse dispositions ;butitmustbecarefullyremarked that this constraint extends onlytowhetiscorporeal; tiouscodesteliguantssfenjoyedtheowt viciousandas aithe ‘unbounded license. Human governments most rest contented with thisexterior orapparent trangllity, andgivethem selves little trouble about the real dispositions of men's minds; butbefore God thethoughts alllie‘open,andperverseinclinations, howeverconcealedfom’men,areasabominable inhissightasiftheyhhadbrokenoutintothemostatrociousactions. Men sufferthemselvestobedazzledbyfalseappearances; butGod has ‘respect to.the Teal dispositions of covery spirit, according” a6they. are ‘virtuous or Yicious, independently oftheactions Which flow "TheHolyScriptures contain tothis th * er intothispurposethe montpointeddeclarations, andinform'usthatbe ‘whomeditatesonlythedestructionofhisneighbour, taflerngNimelffobehurriedawaybyaaitof hatred,isascriminalinthosightofGodastheao- ‘talmurderer;andthathewhoindulgesacovetousSesire ofanother's property is,inHiseetimation, as ‘mich athiefashewhoreallysteals. Tnthisroapect,therefore,thegovernment ofGod / 72 wont av permet xm. coverspict,orrationalbeingsisinfinitelydierent fomthetphuchmenexoroseovermenficetome screeandweeyeimaptas foreramentwhepotasteSstfeyercf SanteoytegmtfGa.Rn FetlectionOfwhichweaughtnevertoTobesight. thMerch101 LETTERCXL OFMoraendPhysicalEvi Wercomplaintsmadeofteevilswhich valinthewor«dationofTienoEro amestakesplace;—more! :‘Thecasofonl’eviscosainathepervoroof Ticlous inclinations, thedispositions ofapiso-Whatisevilorrina,witchieundoutedly theHostironscalamityathegrainimpefoc- truthwithregardtospirit,iteimpoesibleto cenceive¢opedepoetieetuieehytoenwhen thoyovine.romthoeternalBrewofvtyoestein thee foieemai fom rtentheonlyespeofrenderings siesfayniteanegohe Power ofGod Hinvelt "Every spint ailicted toioeisnoceneariymiserableanduslesiesurn£0{iuimyCanotcometsaend:wachthe IaeaIformotdemonsofwickedandinferoalspirits‘Stniesichfotappearconanwhat SeriptaresuggetsontheaechTnddlsmakeajenofthisbtaxmencannotproentobethetetoflrataingthernlowedly beingsnichmoredepravedthanthe BotpaganofmannadereBoek avealreymadiappearthatUneexistanceofao youtamricanwns8 tnycryetnetenootore anyobjectionagainstMentactofthisworld, Shee ce an nee elland inttelysopehorfoeveryThingth casrn cm croee eyeensodatae See centsesof ferfecton.Now,pintaeine‘essentiallyfree, ees ew cisn yseme acewePenieecomet oataealconte oct iyiOmar. beer roca taeeae a nae ‘oftheevilwhiehhecommits; and,consequenty,Ce mace caceeeneSteeteanilaeee peeitroelBeret gee eee weaBe crenageeces rae poke etn solv nana carter che, tpn scx a selena a ere rNBalMicrode ametoemet Een amen gern bom ie Seis omen ec ene‘quencesarecommunicated bymeansofbodies,itis seruycomereerste ShesWtdoceapmeedPate nw mee nett Sei ee arene cee‘thepointofcommitting amurderwouldsnatchthe Sealringseneroeee TeesMeowaemeenca custetytae Seelo peetal fecoteasers ws wu mm father,or,whopreventedhim,doesnottherebyrender‘Wemaynevertheless confidently maintain, thatSisireeencerinet Mthsperncoospepeeeofiswowanbearseee Iniserabieshouldwebe!WefrequentsecthatSegoe S Reeeteseee Sortsersicestne Wwhst'wastended.itcannotbesentedathesameSoS oeee ceethat.theworldwouldbeinfinitelybettergovemedSe canes at eecrushfodeathatyrantbeforehecouldrealizehis Soe iene See eee {hegoodinpouecion ofthepoucealenjoymentof See aea hele,botpain’covatoexecutethlsmaeSeeger wuwrencroFravmoanEnz.875 ‘ofworth; while thegood are oppresredandover- Stheimedbythemostsenateevil,pune,dears,Tmorifestons, lows ofgoods, and fngenera by‘veryspeciesofetlamiy”andthatatastthegoodfalathebamotnaldie,whichappears {0betheprstert ofaleviookingontheworldinthispointofview,oneiatemptedtoelmquestionthesupremewisdomand fookness oftheCreator, boo hazardwhich fomut take great care foavoid. tehMare, LETTERoxn. ReplytoComplaintsoftheEsisenceofPhysicalBi. Sena, nines limited tothe.rset andthemontofeverydelightonlbevery Aiareaiattroefelicityconsstainmental ‘Tanqulityandastisaction,whichare seldomifever coompanted with that brllaney ofcondition which S'couttiered areoch entnechmchie Woesng by those whojudge only from appearances"Taeinmiietney oftemporalgoodthingstoren-aeropytecomes iloreana enwe ome10febectonourrealdestination, DewthdoesSotputs period toourexitence,iaiherrami Eeino ahothor fey which is1endureforover ‘The faculties ofon tou ad ‘our attainments ti”Knowledge,wilen0doubtbecaredtothehigh stpcosaronhnaoatSr Tappinese, depends, ate cannot i an - "Hikeinte perfectionsoftheSupremesicheumencore olyugha Sood,shatthen'shineinthebrightestlustre,and ¢ 376 enermnceoFParmoanamt. ‘tallbecometheprincipalobjectofourcontempla- tion, admiration, andadoration. ‘There,notoa shailourunder fotthemodexhaustsStoresofpureandperfectknowledge,butweshall bhpermittedtohopeforadmiseionintofavourwith theSupremeBeing,adispiteafrthemoste-deringexpressionsofhisTove.How“haprydo Specialyiyiheireallypresthoughte,avoury whichhebestows aremarred bymanyinfusions ofbitterness! Whatwillitthenbe,inthelifetocome,‘whenGodhimselfshallshedabroadAutloveoorKeerte—alove,theeffectsofwhichaallneverbetn.{crrptednorestroyed’‘Thinshallthenceforward constituteafelicityinGnitelysurpassingallthatwe “inonderto inthese MefaC inexpressi roereowingomtheloveofteSupremeBetg, ‘itisnatural¢!onourpart,weshouldbe,pene fatedwithsentiments ofthomostlivelyafection{oBim(TWigDlwod nonsbmolutelyroguesin Ssceapartion,witch WeoadDo incapableofparticipatinginit;‘isposition Costevar,tetaiofwhichiheeof Goa, ‘ourneighbour. ain fofvirtue;then,shouldbeourchief,ouronlyobject{thislife,whereweexistbutforthisend—toBieeidioeneroreren worthyofpartingRupremeandeternalfelicity. of Pointofview,wemastforma © ghooventtwhichBealteinthieetenetthe [Rosseasionofthegoodthingsofthisworotren, wushappy;itirather2situationwhichmoatccaconc1vastpropertywore {hecartanmoanofrenderingunhappy.weight ‘besufferedtocomplain ofadversity ;butadversity:ratherhavetheeffectofconSrmingourvirtue andinthisview,allthecomplaintsofenreepoct- BXISTENCE OF PRYSICAL EVIL. 377 ingthphysicaleisofifarelikewisecompletly meaway. : ‘You have nodifficulty, then, incomprehendingthatGodhadthemostsolidreasonsforsdmiting into theworld somany calamities and miseries, as thewhole obviously contributes tooursalvation.” It isunquestionably true that these calamities are, for ‘the most part,natural consequences ofhuman cor-upton:ainsverythingthatwe,must ineipallyadmirethewisdomoftheSupremeBeing, thoKnowshowfooverrulethemostviciousactionsTorourialhappy naveseached uchatanalyofrue,hedtynotbeenoppressed andtormented bycruelty andinjustice. 1havealready remarked, thatbadactions are ssuchonlywithregardtothosewhocommit them: ihedeternation oftheirsolsoneicimialthe actionits athingpurelycorporeal,nas 4s,consideredIndependent ofthepersonwhocom- mitsi,thereisnothingeithergoodorevilinthe cease."Amasonfallingfromtheroo!ofahouse ‘uponamanascertainlykillshimasthemostdeter-binedaassin.Theactionisabnluelytheane: tthe masonisnotguiltyintheslightestdegree; ‘whereastheassassindeservestheseveresta iment.Thus,howevercriminalationsmaybewith regardtothosewhocommitthem,wemustconsider ‘heminquitediferentlightatheyaffectourselves, orproduce aninfuence onoursain,feoughtthereforetoreflect,thatnothingcan Dfall usbut what Is perfectly consonant tothesovereign wisdom ofGod.‘Phewicked maybe{ulyofinluticetowardswo,butwecannotton ‘whole sufer from it;noone can ever injure us, Ghough hemay greatly hurt himself; andinevery Bingthtcomes 0,passweOughtalwaysfoac- Knowledge God, asifitbefell usimmediately by Aisexpen appointment, Womay,moreover,rst 878naapeermariox oFMAN; ssmuredthatitienotfromcaprice,ormerelytovexSartuatGodteponesTawcreateinwhichwetre <odcereduthattheyestfibtormitaaka urtruehappiness. ‘Thosewhoconsideralevents SnghelonhaeseetnofDing convincedthatGodexercnesapeculiarcarevet ‘iatMarch,176. LETTEROXIIL ‘ThereatDestinationofMan;UnfuinessandNeces- stofAdversity.[LornyouhavenodoubtsremainingwithrespecttotreatquationHowheevnofthisword ‘anbeFeoondled ‘visiontomsoftoCreator!"Thesolutionofiecon: {eotabyfoundedonthereedeetnationofman,and ofotheineligentbeings,whoeeexistenceisnot Iinltedtothisfe,‘Themomentthatwelvesight ofthisimportanttruth,wefindourselvesinvolved 55feeretetperpecyananereceed galyfrtisikwouldsearedbeinpsae %databishwconsistencybetweenthepe ofGodandthedistrasesandmiserieswithwhich‘hiaworldisoppressed. Thotemiserieswoudbe bttooreal;anditwereabeolutelyimpoosibie toexplain,hwthpromprtyofthewicked,anthe"70manygoodpeople,couldconsistwi fheDivinejatice”‘Batnosoonerdowereflectthatthishieisbutthecommencementofourexistence,andthatftisa Titiceofhingicntralychanged,andSoare ‘obligedtoformeverydiferentfoagmentOFthe PylriwhichhiieSupersibeoverproa Thaoalreadyremarked,thattheprosperitywhich vanvoixnss or apvensrry. 870 wweenjoyinthisworldisthereverseofasuitablerepartion foruurefeandforrenderingue Ironyofthefelitywhichhereawaitws,"How: verimportanttoourhappinessthepossession thegoodthingsofthisworldmayspear,this qualitypertainstothemonlyin90farastheyare ImpreedwiththesignatureofDivinegoodneny independent ofwhich‘noearthlypossessionsconaituteourfelicity.ealhapinesifbefundonlyinGodhse; allother delightsarebutanemptyshade,andarecapableofyieldingonlyamomentary satiafaction.‘Accordinglyweseothatthosewhoenjoythemin the greatest abundance are quickly satiated; and this apparent felicity serves onlytoinflametheir thomfromtheSupremeGoed,inteadofbringing emfromtl " C them nearertoHim,Battruefelicityconsistsin fperfect union with God, which cannot subeiet‘withoutaoveandaconfidence inhis.goodnessEanscending‘a tingandthinlverege,8 Certaindispositionofsoul,forwhichwemustbe making preperationintiis "Thisdispositionisvirtue,thefoundationofwhich incontained inthese two great precepta:,‘PhowshaltlovetheLordthyGodwithallhyheart,sthahyeawithalfysrgandithll‘hymind;soaiherwhichiiomiit: ‘Thoushaltlove asthyselfveryotherGnpoitinofgoalwitchdeviaton—*fromthesetwopreceptsisvicious,andaieclutely smmortyioparakeofteapps”tsi heforaviousmantoenfoyhappinessinthe Fifetocome,asforadeatmantoFeliahthepleasure fofanexquisitepieceofmusic.Hemustbefor ‘everexcludedfromit,notbyanarbitrarydecreeof ‘God,butbytheveryhatureofthething;avickous 380 OFTRURHAPPINESS. ‘mannotbeing,fromhisownnature, susceptible of meaFre entereagomomyofho Seca cers ae Taare iepeeaieeo rere meeesaybewithrathatmoshatinigIndeedtheremeron enimernes Romecaceetnrae entmisirectedbyPrintheviewofrenderring:‘metruly everlastingly 7,howoughtthismea craneuy,rch Sayen eee eal i soir comes enemeet towhich liberty issoessential thatnodegreeof ieeeeee omdpeot aeee, So Semoetran, osae Bie ieeestor eaoee Ree ee nee arntthmeeehenreredaeee tates eeakeSe eo Sear, 4 LETTER XIV. Oftrue 1.Conversion ofSinners.Replya fon ‘wrhi iohespeanoother partisMeeswiSacer petromie geet es | eof eo Ci go me oF TRUE MAPPEEsE. 381 whichitisimposeible foramomenttodoubt,the ‘njoymentofthishappinessneceesad ryrequires,on ‘ourpart, acertain disposition, founded onsupreme love'to God,andthemoatperfect chantytowarda‘Ourneighbour; 0thatallthosewhoaredestitute ofthis disposition destroy their own pretensions to celestial felicity; and wicked men arefrom their very nature necessarily excluded from it,itbeing impossible forGod himself torender them happy.FortheDivine Omnipotence extends only tothings‘whichareintheirnatrepossible andlibertyis$0‘essential tospirits thatnodegree ofconstraint can takeplacowithrespect tothem. 1nlybymotives therefore, thatepritecan bedetermined tothat‘whichis.good;now,whatmotivescouldbeproposedtotheapostlesandotherdisciplesofJesusChrist,toembraceavirtuouslifo,more powerful than theinstructions oftheir divine Master, hismiracles, hissufferings, hisdeath andresurrection, ofwhichtheywerewitnesses.Allthesestrikingevents,unitedtoadoctrinethemost sublime, must have excited intheir hearts themost fervent ove and themost profound veneration forGod,whomtheycouldnotbutconsiderandadoreasatoncetheirheavenlyFatherandtheabsoluteLord ofthewhole universe. ‘These lively impres- ‘sions must necessarily have stifled intheir breasts‘everyviciouspropensity, andhaveconfirmedthemmahiesalaryeectonhemindofthe issalut ‘onthemindsof tasnothingiyioftelmiraculous orwienen roachesinthesmallestdegreeontheirliberty, {houghtheeventbesupernatra, "Thogreatre: uisite was simplyaheartdocileanduncorruptedby ‘Viceandpassion.‘Themission,then,ofJesusChrist {ntotheworldproducedinthemindsofthespos- tlesthis disposition, #0necessarytotheattainment andtheenjoyment ofsupreme happiness; andtht rmissionstillsuppliesthesamomotivestopursuethe arte srt vec, py i tiawithout prejudice, thehistoryofit,andseriously to Binacitatepe coca Pee er Fronts anc eras,pleswhlchwehavelaiddown,thatspilaeanbe Se et amen, ihati ums na Sp tee alg Rl pee ee py SENS! Seemaymeanextremely well,andconsider themselves ELS des ome rer Baa Oiseearn Soot ite Ba eeGotan etter nc, OSEAN eesSaelves areneRe cdIacknowledge thatthisobjectionappearstomeLev natura hares oeEa tte tee sbeiactes Micra beets, 2Eon wtpte woo ery, orTRUE mAPPINess. 383 tsifTweremaintaining thatthepowerofmanis Sificieat forhisconversion; butthisreproach af fects menot,a81am conscious ofintendingtoplace {Eefoodnen aGod iecert ght te ‘work ofconversion, man makes perfect use ofhis Iiberty, wich inuausceptible ofconstraint but ‘man always determined bymotives. Now these Rotives areugpeiedtyIhecieintancen nd onjunctures offiscondition.‘Theydependen Stely'on Dine Frovidence,which’roglates ‘all rents conformably tothe laws ofsovereign wis-dom.”ItisGod,therefore, whoplacesmenevery {fatent incircutustances tho mos favourably andffomwhichtheymayderivemotivesthemostpowrfl toproduce their conversion; sothat men are ways indebted toGod forthemeans which promote their salvation.1havealreadyremarked,thathoweverwickedtheactions ofmen may be,they have nopower over their consequences, and that God, when hecreated theworld,aranged thecourseofalleveraotatverymanshouldbeeveryinstantplacedincircumStanees fohim themost talutary.” Happy theman ‘who hewiadom foturn them 10good decoant!"Talsconvictionmustoperatefausthehappiesteffects;unboundedlovetoGod,withfirmrelianceonhis andthepavestcharitytowardsStr gious esoeSpreme Dgat ‘ated an itis consolatory, arAESHswithitethemoe‘sthimeadefecealy Propareusforheenjoymentofliese ~PSRAare 901. tare rrmar TrePandeinyHeFS ‘ofTruth,andClassesofInformation derioedfromit. ‘Havinotakenthelibertytolaybeforecertian haymenreat Seacme rateclrtai Shon abrorecrentee iletatoe chet at aeIshallnowhavethehonourof to:stan temecrate ledge,andthemeanswehaveofbeingassuredofemiascaraca we coraieecanaaint ok Epps miescceen Ghee ree Bheterna aainde Seahatcnantat Glyarate Sareea epee RaoeaeeutERT cityete moakemestor: seeciaraaiemess necessary thatweshouldbeinaitiontoedge Horcamacemenceae he effectIremark, first,thatalltruthswithinourreachemia aner ncn teactinaesenate inalMaate sete? aerate teeSasha iieere see‘threeclassesallhumanknowledgeiscom-| mownxxow.E008. 35 Proofsofthefstclasarereducibletothe setaenandaretharexpressed:hist,forstoomconincedoftby ssdeofyee. ‘i'sthos{snowthatthemagnetatracteirom,becnateTecandexperiencefurnishesmewilt {ncontestable proofsofiefackTruthafhsclase tocallodseanhe, becuasetheyarefoundedonthe tengooronexperience.rosofhecodcanaefoundedonrath sation:TRrnfrLamademe rin penofjustTanning.orbyforopps. iianprint feeer, whichprescrbesrulesforteanningconsequently. visthasweknowthatthethreeanglesofarectTineatanglearetogetherequaltotorightanglesInthincanedonotsayTsceiorthatiysesnesConvincemeofitybutamserirodofafrthby Shrove ofressning. Truths ofthis clase areCalledimuiecaty andherewemustrankallthetraofgooey cnteereenga uchatheyaeeipportedbydemonstration.” You faustbeventethtuchtrotavewhollydifer xtfomthoeofthefatclas,sopportofwhich ‘readducenootberproofsbutthenetses,oFexperHence,wichaneureunthatthefactinoy‘WermnynotknowthecauseofieInteexanOfthemunqnetswedonotknowhowtheasiractonOfthironiesnecenaryeectofthentareofthemagnetand’ofironybutwearenttheles.con: edofherthoftheetFrofte Claseargascertain‘ thowsoftheect {heprotswhich"wehaveofthemare‘entreaifRfroceod othethirdclaseoftrata,thatoffit, tothethird . switth'we boleve becuse persone Worthyofeed, Ritemorbenwe 086 rommaiowoFwomanxhewiEDoE. ‘Thaitrum,forseveraleretalepersonshansae wentgfehislnccordingtyinchalKarric You believe,nodoubt,thattherewasformerly« FrolohmemasteroftheKingiomofers,‘masterntylomeclytetsichporwonoteox, irate‘achapersonever. Burwebelovelt'ontheauthorityoftheauthorsToubtofthelrAdel.Botfoayfetbeposse irSdelity.Butmayitno {hattheweauthorshaveconcertedtodecavewat ‘Wehaveeveryreasontorejectsuchaninainuation; sandweareasmachconvincedofthetruthofthesefact,atTeastof&greatpartofthem,asoftruthsOfthefirstandsecondclanses.‘Theproolsoftheeethree‘classesoftruthsareextremelydiferent;butiftheyaresolid,eachinitingtheymanogalyprodace conviction.You ‘cannotpossiblydoubtthatRussiansandAustrians BravebeenatBerlin,thowghyoudidnotseethem: ‘his,thea,istoyouatruthofthethirdclos,aapuseliersitonthereportofother;butioweit ‘oneofthefrstclas,because1sawthem,and‘conversed withthem;andmanyotherswereasfaredoftheirpresencebymeansofthelrwenses. ‘You have, nevertheless, a8completeconvictionof {thefactaswehave.‘BetMoreh,170, i mmorvob — An32044 —__.2£044074360 Theborrowermustretumthisitemonorbeft thelast date stamped below. Ifanother us places arecall forthisitem, theborrower wibenotifiedofthe need for anearlier return. 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