This difficulty perplexed Sir Isaac Newton all his life, and he never discovered the mode of making a refracting telescope which would obviate it. But M. Dolland, an optician, reflecting that the very same difficulty must have presented itself to the Maker of the eye, determined to ascertain how he had obviated it. He found that the Maker of the eye had a knowledge of the fact that different substances have different powers of refracting or bending the rays of light which pass through them, and that liquids have generally a different power of refraction from solids. For instance, if you put a straight stick in water, the part under water will seem bent at a considerable angle, while if you put the stick through a little hole in a pane of glass it will not seem so much bent. He further discovered that oil of cassia had a different power of refraction from water, and the white of an egg still a different power. He discovered also that the first lens of the eye, the aqueous humor, is very like water; that the crystalline lens is a firm jelly, and that the vitreous humor is about the consistency of the white of an egg. The combination of these three lenses, of different powers of refraction, secures the correction of their separate errors. He could not make telescope lenses of jelly, nor water; therefore, he could not make a perfect achromatic telescope, but he learned the lesson of mutual compensations of difficulties which the Maker of the eye teaches the reflecting anatomist, and procuring flint and crown glass of different degrees of refraction, he arranged them in the achromatic lens so as nearly to remedy the defect.
I think that you will at once admit that Dolland's attempt to remedy the evils of confused sight in the telescope indicated a desire to obtain a precise and correct view of the objects; and that his success in constructing an instrument, nearly perfect, for the use of astronomers, gave evidence that he himself had a clear idea of that perfect and accurate vision which he thus attempted to bestow on them. Shall we then imagine any inaccuracy in the sight of Him, who not only desired, but executed and bestowed on us, an instrument so perfectly adapted to the imperfections of this lower world, and whose very imperfections are the materials from which he produces clear and perfect vision? No! in God's eye there are no chromatic refractions of passions, or prejudice, or party feeling, or self-love. He sees no reflected or refracted light. O Father of Light! with whom is no variableness, or shadow of turning, open our eyes to behold Thee clearly!
Our text thus leads us to a knowledge of God's character, from the structure of the bodies he has given us. He that formed my eye sees. Though my feeble vision is by no means a standard or limit for his Omniscience, yet I may conclude that every perfection of the power of sight he has given me existed previously in him. Has he endowed me, a poor puny mortal, the permanent tenant of only two yards of earth, with an eye capable of ranging over earth's broad plains and lofty mountains, of traversing her beauteous lakes and lovely rivers, of scanning her crowded cities, and inspecting all their curious productions, and specially delighting to investigate the bodily forms of men, and their mental characters displayed on the printed page? Has he given me the principle of curiosity, without which such an endowment were useless? Then most undoubtedly he has Himself both the desire to observe all the works of his hands, and the power to gratify that desire. The Former of the eye must of necessity be the great Observer.
Wheresoever an eye is found of his handiwork, and wheresoever sight is preserved by his skill, let the owner of such an instrument know that if he can see, God can, and as surely as he sees, God does.
If it is possible for us to behold many objects distinctly at once, it is not impossible for God to behold more. If he has given us an eye to look from earth to heaven, then his eye sees from heaven to earth. If I can see accurately, God's inspection is much more impartial. And if he has given me the power of adjusting my imperfect vision to the varying lights and shades of this changing scene, let me not dream for a moment that he is destitute of a corresponding power of investigating difficulties, and penetrating darknesses, and bringing to light hidden works and secret things. God is light. In him is no darkness at all. Neither is there any creature that is not manifest in his sight, but all things are naked and opened to the eyes of him with whom I have to do. He has seen all my past life—my faults, my follies, and my crimes. When I thought myself in darkness and privacy, God's eye was upon me there. In the turmoil of business, God's eye was upon me. In the crowd of my ungodly companions, God's eye was upon me. In the darkness and solitude of night, God's eye was upon me. And God's eye is on me now, and will follow me from this house, and will watch me and observe all my actions, on—on—on—while God lives, and wheresoever God's creation extends.
"O God, Thou has searched and known me;
Thou knowest my down sitting and mine uprising;
Thou understandest my thoughts afar off.
Thou compassest my path and my lying down,
And art acquainted with all my ways
For there is not a word in my tongue,
But, lo! O Lord, Thou knowest it altogether.
Thou hast beset me behind and before, and laid thine hand upon me.
Such knowledge is too wonderful for me!
It is high, I can not attain unto it;
Whither shall I go from thy Spirit?
And whither shall I flee from thy presence?
If I ascend up into heaven, Thou art there,
If I make my bed in hell, behold, Thou art there!
If I take the wings of the morning,
And dwell in the uttermost parts of the sea,
Even there shall thy hand lead me,
And thy right hand shall hold me.
If I say, 'Surely the darkness shall cover me,'
Even the night shall be light about me;
Yea the darkness hideth not from thee,
But the night shineth as the day,
The darkness and the light are both alike to Thee."
FOOTNOTES:
[1] Reid's Chemistry, II. § 37.
[2] Johnson's Turner's Chemistry, § 341.