The principles of light and color: including among other things the harmonic laws of the universe, the etherio-atomic philosophy of force, chromo chemistry, chromo therapeutics, and the general philosophy of the fine forces, together with numerous discoveries and practical applications .. . obviatesthe difficulty by flattening the crystallinelens in proportion as objects are distant, andletting it shrink up into greater thick-ness as objects are near. The reader mustremember that this lens is circular like thedouble convex glasses in a pair of spectacles when round, onlyit is immensely elastic
The principles of light and color: including among other things the harmonic laws of the universe, the etherio-atomic philosophy of force, chromo chemistry, chromo therapeutics, and the general philosophy of the fine forces, together with numerous discoveries and practical applications .. . obviatesthe difficulty by flattening the crystallinelens in proportion as objects are distant, andletting it shrink up into greater thick-ness as objects are near. The reader mustremember that this lens is circular like thedouble convex glasses in a pair of spectacles when round, onlyit is immensely elastic, while all around the edges it is encir-cled by a membrane or suspensory ligament which is like a plaitedruff. Attached to this is the ciliary muscle, containing agreat number of fibres (see fig 199), which under the influenceof the ciliary nerves is made to contract or expand and thusmodify the shape of the lens itself so rapidly and easily that weare scarcely conscious of the process. 8. The Optic Nerve. Fig. 200, shows the chiasm or unionof the two optic nerves at 2 by means of which the two actualimages, one on each retina, which are produced by the exter-nal light, are blended into one. At that place a partial de-cussation occurs and the nerve fibres have been compared to the. balls. Nerves cantia. Fig. 200. The OpticNerves. 1. 1, the two eyi -Chiasm of Optic 3. Corpora Albi- 4. PonsVarolii. 6. MedullaOblongata. 7, 8, q, 10, II,12, 1}. are respectively the3d, 4th, 5th, 6th, 7th, 8th,and 9th pair of nerves. 538 VISION. four lines by which two horses are guided, the lines of eachside passing, to both horses. Some fibres cross from theretina of one eye-ball to the other ; some from one side of thebrain to the other ; some from the eye on one side to the brainon the other; and some from each eye to the same side of thebase of the brain. (Hartshorne.) Huxley does not considerthe Olfactory and Optic Nerves as true nerves, but rather pro-cesses of the brain. The
Size: 1388px × 1799px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectcolor, booksubjectpho
