Barrow, Isaac, Lectiones opticae & geometricae : in quibus phaenomenon opticorum genuinae rationes investigantur, ac exponuntur: et generalia curvarum linearum symptomata declarantur

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            <s xml:id="echoid-s238" xml:space="preserve">
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            _Democrito_ jam olim, ejúſque ſequaci (dicam an ſimio? </s>
            <s xml:id="echoid-s239" xml:space="preserve">) ſuboluer@t
              <lb/>
            _Epicu
              <unsure/>
            ro_. </s>
            <s xml:id="echoid-s240" xml:space="preserve">Quod ſanè malim adſumere, vel ſupponere, quam poſt tot
              <lb/>
            alios operoſo niſu comprobare. </s>
            <s xml:id="echoid-s241" xml:space="preserve">Certè (quo breviſſimè tangam hanc
              <lb/>
            quæſtionem) ſic in alia qualibet evenit ſenſione, (quidni pariter in vi-
              <lb/>
            ſu?) </s>
            <s xml:id="echoid-s242" xml:space="preserve">non ut ſenſus in objecta feratur, ſed ut ipſa ſe ſenſibus imprimant;
              <lb/>
            </s>
            <s xml:id="echoid-s243" xml:space="preserve">immediato nempe contactu, vel medii cujuſdam ſeu projecti, ſeu com-
              <lb/>
            moti interventu. </s>
            <s xml:id="echoid-s244" xml:space="preserve">Tum ratio vetat, ut ex ocello quicquam in immenſam
              <lb/>
            adeò circumquaque diſtantiam credamus emanare; </s>
            <s xml:id="echoid-s245" xml:space="preserve">neque quod ſic
              <lb/>
            emanet in eo quidpiam aptum natum deprehendimus. </s>
            <s xml:id="echoid-s246" xml:space="preserve">Totus enim-
              <lb/>
            vero pellucidis humoribus aut membranulis conſtat opacis, ad tranſ-
              <lb/>
            mittendam lucem, vel ad eam excipiendam, aptiſſimè, ſed ad progig-
              <lb/>
            nendam à ſe vel ejaculandam haudquaquam comparatis. </s>
            <s xml:id="echoid-s247" xml:space="preserve">Quòd ſi lu-
              <lb/>
            cem ipſe profunderet, inſitiſque radiis attingeret objecta, quidniden-
              <lb/>
            ſiſſimis in tenebris hoc præſertim faceret, & </s>
            <s xml:id="echoid-s248" xml:space="preserve">feles vel (Hiſtoricis ſi
              <lb/>
            placet) _Tiberii_ fieremus omnes? </s>
            <s xml:id="echoid-s249" xml:space="preserve">Quæ, dico, lucis externæ tam indiſ-
              <lb/>
            penſabilis ad viſum neceſſitas eſſet? </s>
            <s xml:id="echoid-s250" xml:space="preserve">συνωγας equidem Platonicæ. </s>
            <s xml:id="echoid-s251" xml:space="preserve">
              <lb/>
            Sonum audio, vim non capio. </s>
            <s xml:id="echoid-s252" xml:space="preserve">Demum ab objectis, etiam à tergo ſitis,
              <lb/>
            circumfuſas ſpecies quas vocant, ad oculos deportari, ſuíque percep-
              <lb/>
            tionem efficere, cùm à ſpeculis, tum ab aliis innumeris perquam ob-
              <lb/>
            viis experimentis compertum habetur; </s>
            <s xml:id="echoid-s253" xml:space="preserve">illarum igitur eſſicaciæ quidni
              <lb/>
            commodiſſimè viſionem adſcribamus? </s>
            <s xml:id="echoid-s254" xml:space="preserve">ſatìs hæc illam quam adſumimus
              <lb/>
            vulgarem jam hypotheſin adſtruunt, quam & </s>
            <s xml:id="echoid-s255" xml:space="preserve">totus dicendorum tenor
              <lb/>
            luculentè confirmabit.</s>
            <s xml:id="echoid-s256" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s257" xml:space="preserve">V. </s>
            <s xml:id="echoid-s258" xml:space="preserve">Cùm verò multa viſum aſſiciant diverſimode, puta lux, lumen,
              <lb/>
            dies, crepuſculum, colores,
              <unsure/>
            rerum imagines, phaſmata; </s>
            <s xml:id="echoid-s259" xml:space="preserve">nec tamen
              <lb/>
            abſque luce. </s>
            <s xml:id="echoid-s260" xml:space="preserve">(Præſente nimirum aut prævia) quidvis horum aliquid
              <lb/>
            peragat, perſpicuum eſt lucis hîc præcipuas partes, primariam effica-
              <lb/>
            ciam fore. </s>
            <s xml:id="echoid-s261" xml:space="preserve">Quinimo rem ſedulò penſitantes, eò deveniemus, opinor,
              <lb/>
            ut varias his omnibus adnexas apparentias non aliunde quàm ex diverſi-
              <lb/>
            modâ lucis unius operatione putemus proficiſci. </s>
            <s xml:id="echoid-s262" xml:space="preserve">Cùm nempe lux ſit
              <lb/>
            illud quicquid ſit quod à corpore lucido (quale ſtella, ignis, flamma)
              <lb/>
            proveniens immediatè viſum afficit, lumen nil videtur aliud quàm lux
              <lb/>
            in corpuſcula quædam opaca (ſeu lucem non penitùs excipientia)
              <lb/>
            πς ωειΕΧονη interſperſa impingens, nec non ab iis in omnes undique
              <lb/>
            partes reſiliens; </s>
            <s xml:id="echoid-s263" xml:space="preserve">quæ ſcilicet in oculum itineri ſuo expoſitum tumultu-
              <lb/>
            ariè delapſa confuſam quandam apparentiam excitat; </s>
            <s xml:id="echoid-s264" xml:space="preserve">quàm, ſi fortior
              <lb/>
            ſit, eique prorogandæ lucens præſtò ſit, appellamus diem; </s>
            <s xml:id="echoid-s265" xml:space="preserve">at ſi de-
              <lb/>
            bilior fuerit, ejúſque fons abſceſſerit, crepuſculum dicimus. </s>
            <s xml:id="echoid-s266" xml:space="preserve">Etiam
              <lb/>
            color nil fermè videtur aliud, quam lux à corporibus quibus </s>
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