[ 12 ]
lours. For because the light-weight that comes from the
Point Q goes to the purpose g, commissioned military officer the sunshine that comes from different Points P and R of the article, can move to move to move to Points
pand r (as is manifeſt by the fixth Axiom;) ſo
that every purpose of the article fhall illuminate a correſpondent purpose of the image, and there-
by build an image just like the Object in form and color, this solely excepted, that the image the image inverted.
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| isaac newton book |
And this can be this can be of that
vulgar Experiment of caſting the Species of Ob-
jects from abroad upon a Wall or Sheet of written report in a very dark space.
În like manner, once a person views any Object
PQR, [in Fig. 8.] the sunshine that comes from
the ſeveral Points of the article is commissioned military officer refracted
by the tranſparent skins and humours of the
Eye, (that is by the outward coat EFG known as
the membrane tissue layer, and by the cryſtalline hu-
mour A B that is on the far side the Pupil m k) on converge and meet once more at ſo several points in
the bottom of the attention, and there to color the
Picture of the article upon that skin (called the membrane Retina) with that the lowest of the attention is roofed.
For Anatomiſts after they have
taken oif from the lowest of the attention that out-
ward and moſt thick Coat known as the meninges Ma-
ter, will then ſee through the diluent Coats,
the Pictures of Objects spirited painted there-
And theſe footage propagated by Mo-
tion on the Fibres of the Optick Nerves in-
to the Brain, area unit the cauſe of Viſion. For ac-
cordingly as theſe footage area unit good or im-
perfect, the article the article absolutely or imperfect-
ly.
on
[ 13 ]
ly. If the attention be colorful with any color (as in
the Diſeaſe of the Jaundiſe) ſo on tinge the
Pictures within the bottom of the attention thereupon
Colour, then all Objects seem colorful with the celebrity color.
If the humours of the attention by
old Age decay, ſo as by ſhrinking to form the
Cornea and Coat of the Cryſtalline humour grow praise than before, the sunshine won't be re- fracted enough, and for wish of a ſufficient Re- fraction won't converge to the lowest of the
Eye however to ſome place on the far side it, and by con-
fequence paint within the bottom of the attention a con- fuſed image, and in step with in step with in step with this image the item can seem con- fuſed.
this can be this can be of the decay of fight
in old Men, and ſhews why their Sight is mend- ED by Spectacles. For thoſe umbellate umbellate fup- ply the defect of plumpneſs within the Eye, and by encreaſing the Refraction create the Rays con- verge ſooner ſo on on at the lowest of the attention if the Glafs have a due de- gree of convexity.
and also the contrary happens in ſhort-lighted Men whoſe Eyes ar too plump.
For the Refraction being currently too nice, the
Rays converge and convene within the Eyes before they are available at the bottom; and so the
Picture created within the bottom and also the Viſion
cauſed thereby won't won't, unleſs the
Object be brought FO close to the attention as that the
place wherever the connexion Rays convene could also be removed to the lowest, or that the plump- neſs of the attention be set out and also the Refracti- ons diminiſhed by a Concave-glaſs of a due de- gree of Concavity, or laſtly that by Age the
Eye
Bized by Google
[ 14 ]
Eye grow blandish until it return to a due Figure i
For thort-ſighted Men fee remote Objects beſt
in Old Age, and so they're accounted
to have to own to own.
A X. VIII.
AN Object ſeen by Reflexion or Refraction,
appears therein place from wherefrom the Rays af.
ter their laſt Reflexion or Refraction diverge in
falling on the Spectator's Eye.
If the article A[in Fig. 9.] be ſeen by Reflexion
of a Looking-glaſs m n, it hall seem, not in its correct place A, however behind the Glaſs at a, from wherefrom any Rays AB, AC, AD, that ensue one and also the fame purpose of the article, do when their Reflexion created within the Points B, C, D, di- verge in going from the Glaſs to E, F, G, wherever they're incident on the Spectator's Eyes.
For theſe Rays do build the celebrity image within the bottom of the Eyes as if they'd return from the article extremely placed at a while not the inter- poſition of the trying trying and every one Vifion is formed consistent with the place and ſhape of that image.
In like manner the article D [in Fig. 2.] ſeen
through a Priſm, seems not in its correct place D, however is thence tranſlated to ſome different place d ſituated within the within the Ray F G drawn backward from F to d.
And ſo the article Q [in Fig.10.] ſeen through
the Lens AB, seems at the place from wherefrom the Rays diverge in pafling from the Lens to the attention. currently it's to be noted, that the Image of
the
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