"Seem to be colored? Why, they are colored! my suit was colored with a blue dye, and there's a kind of green dye in grass: I've got it on my stockings and handkerchiefs many a time."
"The juice, or fluid, in the grass looks green, just as the grass does, because its particles are so arranged that they absorb all of the light except the green rays, and those they reflect. The substance of those roses out there in the garden absorbs all except a red part of the light, and reflects that. Your collar reflects all the colors in the light, and that makes it white, which is the mixing of all the colors together in certain proportions. My spectacle-case looks black, because it absorbs the light without reflecting any of it.'"
"I don't believe that," replied Felix: "I shall always believe things are colored in themselves, without any regard to the light. How do you know that there are different colors in light? You can't see any thing but a kind of yellow."
"You can't see yellow, unless it is reflected."
"Why, yes, you can. Look over in that field; it's just as yellow there where the sunshine falls as can be; and where it falls between the trees here in the orchard, the green looks yellowish, while it is just bright green under the trees; and the sun itself is just as yellow as can be."
"The grass has been mowed out in that lot, so the sun has dried it, and changed the substance of it so that it reflects more yellow rays. I suppose that here in the orchard more of the rays striking the parts that are not protected by the trees gives a different reflection. As for the sun being yellow, it isn't always yellow; that is, I mean it doesn't always look yellow; I have seen it look quite red."
"If it isn't yellow, I'd like to know what color it is!" exclaimed Felix, rather impatiently.
"I don't suppose it is any color at all, though it gives the impression of a good many colors to our minds: color is nothing but a sensation produced by the kind of light that is reflected to our eyes. But light that is not separated at all, gives us only a sensation of whiteness. I don't suppose the sun would look yellow to us if we could see it without looking through any air. The air even changes the direction of the sunlight so as to make the sun appear to us to rise a little while before it does rise."
"I don't see how folks found out all that, and I don't believe they have! I'll bet they made it all up!"
"I have a fine prism at home: we'll go up in the sky-room this afternoon, and I will separate some light into its different colors. But look here, Felix! see! When I throw this ball against the floor in a slanting direction, notice how it bounds back the other way in just such a slant line as I threw it in from this way. Light does just like that, and heat too: if a ray of light strikes a plane surface at a slant, it is reflected the other way in exactly the same slant. And it's something so when light passes through any transparent substance: it comes out the other side just as it went in. That is, if it goes in at a slant, it comes out at the same slant it went in at, making an angle; but if it passes in at a right angle, as I throw this ball against the floor, it comes out and goes on the other side, in the same straight line."