For, Pyrophilus, that the proposed Enquiry may be of moment to him that searches after the Nature of Colour, you'l easily grant, if you consider, that whereas Perfectly Opacous bodies can but reflect the incident Beams of Light, those that are Diaphanous are qualified to refract them too, and that Refraction has such a stroak in the Production of Colours, as you cannot but have taken notice of, and perhaps admir'd in the Colours generated by the Trajection of Light through Drops of Water that exhibit a Rain-bow, through Prismatical glasses, and through divers other Transparent bodies.
We can produce this phenomenon at pleasure, by employing any one of the many substances which are known to refract light in that peculiar manner.
That, finally, one could also fashion out of it triangular prisms, or prisms with as many sides as one would, of which neither the sides nor the bases would refract the perpendicular ray, although they would yet all cause double refraction for oblique rays.
She alters his personal equation when he gets tired, makes him see a small star differently from a bright one, gives his instrument minute twists with heat and cold, sends currents of warm or cold air over his locality, which refract the rays of light, asks him to keep the temperature in which he works the same as that outside, in order to avoid refraction when the air enters his observing room, and still will not let him do it, because the walls and everything inside the room, being warmed up during the day, make the air warmer than it is outside.
White luminous fogs, like curtains of gauze, too thin to dim the general brightness, yet dense enough to invest the whole scene with a silver robe of mystery, and to refract the light and compel it to shine in great circles of prismatic colours!
This done, I took the first prism in my hands and turned it to and fro slowly about its axis, so much as to make the several parts of the image, cast on the second board, successively pass through the hole in it, that I might observe to what places on the wall the second prism would refract them.
A box of very thin common glass would be hard to see in a bad light, because it would absorb hardly any light and refract and reflect very little.
If you so live as to refract the life of Christ and turn it upon them and thus stamp upon them a holier life, you have not lived in vain. To set the life of Christ in its purity and beauty before some one and influence him, though only a little, to live better and love Jesus more, is a work the worth of which can never be computed.
Often in that nameless discouragement before unfinished tasks, unfulfilled aims, and broken efforts, I have thought of how the creative Word has fashioned the opal, made it of the same stuff as desert sands, mere silica not a crystallized stone like a diamond, but rather a stone with a broken heart, traversed by hundreds of small fissures which let in the air, the breath, as the Spirit is called in the Greek of our New Testament; and through these two transparent mediums of such different density it is enabled to refract the light and reflect every lovely hue of heaven, while at its heart burns a mysterious spot of fire.
"Not possible, Major," replied the pretty physicist. "The force field, as you know, is made up of electronic impulses of pure energy. By shooting these impulses into the air around a certain area, like the settlement at Olympia, we can refract the methane ammonia, push it back if you will, like a solid wall.