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-s385" xml:space="preserve">
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            quam infinitos ſupponere fas eſt) idoneum reperiens. </s>
            <s xml:id="echoid-s386" xml:space="preserve">Ità vulgare pro-
              <lb/>
            nunciatum interpretor; </s>
            <s xml:id="echoid-s387" xml:space="preserve">id quod alias rigidè ſumptum haud verum du-
              <lb/>
            co. </s>
            <s xml:id="echoid-s388" xml:space="preserve">Nec enim idem corpus eodem temporis puncto diverſas in partes
              <lb/>
            contendere, vel adniti; </s>
            <s xml:id="echoid-s389" xml:space="preserve">ſed nec eandem præciſè medii partem è diver-
              <lb/>
            ſis locis accedentes corporum motus excipere quiſquam conceperit,
              <lb/>
            opinor, aut ego conceſſerim; </s>
            <s xml:id="echoid-s390" xml:space="preserve">non certè magìs quam idem corpus unà
              <lb/>
            plures locos occupare, vel eundem locum plura ſimul corpora ſuſcipe-
              <lb/>
            re; </s>
            <s xml:id="echoid-s391" xml:space="preserve">ad iſtum modum intellecta dicta ſuppoſitio totam unà cum radiis
              <lb/>
            lucidis naturam, omnem, utmihi videtur, Phyſicam permiſcebit. </s>
            <s xml:id="echoid-s392" xml:space="preserve">In
              <lb/>
            noſtro rem explicandi modo nihil durius obverſari video, quàm ut hinc
              <lb/>
            divinæ potentiæ, ſapientiæque vis magìs eluceſcat, in luce ſic efforman-
              <lb/>
            da, tam ejus effectricibus particulis admirabilem exilitatem, incom-
              <lb/>
            prehenſibilemque velocitatem impertiendo, quæ prorſus ei neceſſariæ
              <lb/>
            fuerunt, ut ſenſionem efficeret, & </s>
            <s xml:id="echoid-s393" xml:space="preserve">reliqua tam utilia ei deſtinata mu-
              <lb/>
            nia obiret. </s>
            <s xml:id="echoid-s394" xml:space="preserve">Sanè lucis corpuſculum unum ab arenula quavis litorea
              <lb/>
            pluſquam eâ fortaſſis proportione ſuperatur, quâ tota quanta quanta
              <lb/>
            eſt mundana moles arenulam iſtam excedit; </s>
            <s xml:id="echoid-s395" xml:space="preserve">id quod non ita cenſe-
              <lb/>
            bit abſonum, quiſquis ad complures ſatìs obvias apparentias men-
              <lb/>
            tem adverterit.</s>
            <s xml:id="echoid-s396" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s397" xml:space="preserve">Subnotandum eſt porrò duas has fundamentales hypotheſes, ſic ac-
              <lb/>
            ceptas, innumeris adniodum familiaribus experimentis confirmari.
              <lb/>
            </s>
            <s xml:id="echoid-s398" xml:space="preserve">Quovis enim in loco ubicunque collocati objecti lucentis vel illuſtrati
              <lb/>
            quæcunque deſignabilis particula conſpicitur oculo, repræſentatur in
              <lb/>
            ſpeculo, modò nihil objiciatur ab eo rectâ delabentes radios interclu-
              <lb/>
            dens; </s>
            <s xml:id="echoid-s399" xml:space="preserve">eadem verò ſtatim oculo ſubducitur, & </s>
            <s xml:id="echoid-s400" xml:space="preserve">penitus obumbratur,
              <lb/>
            ſi quid opaci corporis directum intercipiens radiorum iter obtendatur. </s>
            <s xml:id="echoid-s401" xml:space="preserve">
              <lb/>
            Etiam foramen utcunque tantillum ſufficit trajiciendis radiis quibus tota
              <lb/>
            quantivis objecti facies obverſa depingatur. </s>
            <s xml:id="echoid-s402" xml:space="preserve">Et porrò quam nullà poſſit
              <lb/>
            apprehendi tam exigua lucidi pars, à qua non lux ad oculum defluit,
              <lb/>
            perſpiciliorum uſus apertiſſimè monſtrat. </s>
            <s xml:id="echoid-s403" xml:space="preserve">At pergo.</s>
            <s xml:id="echoid-s404" xml:space="preserve"/>
          </p>
          <p>
            <s xml:id="echoid-s405" xml:space="preserve">X. </s>
            <s xml:id="echoid-s406" xml:space="preserve">3. </s>
            <s xml:id="echoid-s407" xml:space="preserve">Lucis radius quilibet alteri medio perpendiculariter incur-
              <lb/>
            rens, aut rectà progreditur, ſiquidem cedente medio procedere valet,
              <lb/>
            aut in partes directè contrarias (hoc eſt in ſe, vel in ſuam retro ſemi-
              <lb/>
            tam) repellitur. </s>
            <s xml:id="echoid-s408" xml:space="preserve">Experientiâ firmatur hæc hypotheſis; </s>
            <s xml:id="echoid-s409" xml:space="preserve">& </s>
            <s xml:id="echoid-s410" xml:space="preserve">rationi
              <lb/>
            quoque conſentanea eſt; </s>
            <s xml:id="echoid-s411" xml:space="preserve">necenim ulla poteſt excogitari cauſa, cur in
              <lb/>
            unas potius quàm in alias partes deflectatur; </s>
            <s xml:id="echoid-s412" xml:space="preserve">igitur in nullas. </s>
            <s xml:id="echoid-s413" xml:space="preserve">Quinimô
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            ſiverum ſit omne patiens, aut percuſſum vim inferenti poſitivâ quâdam
              <lb/>
            vi repugnare, perſpicuum videtur eò reſiſtentiam dirigi, unde vis ingru-
              <lb/>
            ebat; </s>
            <s xml:id="echoid-s414" xml:space="preserve">ejúque conſequenter effectum abſolutè loquendo, tantùm </s>
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