CHAPTER XXVIII.

MORE ABOUT COLOR.

[Sidenote: How color is made.]

You see that the color of a thing is not a part of the thing itself. It is something which the thing throws off or lets pass through it. The color of a thing depends upon what a thing will do to the light when the light comes to it. It has no color in the dark. Its color is made out of the light that shines on it.

[Sidenote: Color not a fixed thing shown in various ways.]

Color is something that is made every moment. The color that you see now in any thing is made now, out of the light that is shining. If a piece of cloth looks blue to you, it makes the blue color out of the light while you are looking at it. The dyer did not really make the color. The dye that he put it into altered the cloth so that it would make a blue color go to your eye from the light that comes to the cloth.

You have seen changeable silk. Here the colors change as the silk is moved. The reason is that, as the light strikes it in different ways, different parts of the light are reflected from it, and come to our eyes. For the same reason, as the hanging prisms of a chandelier or a girandole move, you see the colors in them change. So when the wind moves the tree covered with ice, or blows along the little pieces scattered on the ground, you see the same play of colors.

There is another fact which shows that color is not a fixed thing. It changes with different kinds of light. The light of a lamp or of a fire is not exactly like the light of the sun. It is not so white, and so we very often find that a thing which we have looked at in the evening has quite a different color when we come to see it by the sunlight. A piece of cloth that looks white by candlelight may look quite yellow the next morning by the light of day.

[Sidenote: Variety of colors in flowers.]

I have told you in Part First about the great variety of colors in flowers. All these colors are made out of the same light. If a flower is yellow, it is because the yellow part of the light is sent to our eyes, while the flower, as we may say, keeps the other six colors to itself. Some flowers are more yellow than others. The reason is that they reflect more of the yellow part of the light. Some leaves are greener than others because they send to our eyes more of the green part of the light.

In some flowers there are different colors close by each other. In the iris you have the blue and the yellow. Here one part of the flower sends to your eye the blue part of the light, and another the yellow part. In some flowers you see white close by other colors. Thus one kind of poppy is white except by the edges, which look as if they had been dipped in a red dye. How singular it is that, while some parts of the flower are fitted to send to your eye one color alone, the other parts send all the seven colors mixed together so as to make a white color!

[Sidenote: Shading off of colors.]

Look, too, at the gradation of colors. This is very beautiful in some flowers. In some roses you see the red color shade off into white. You look at one of its leaves, and see a part of it that is quite red, and as your eye goes from this part, the red is less and less deep, till at the very edge it is all gone. Now remember that the more of the red part of the light is reflected, and the less there is of the other parts, the greater is the redness, and see how wonderful all this is. How nicely must the flower be made in order to give this shading off! In the very red part a great deal of the red color is sent to our eyes, and none of the other colors. Then from the part close by it a little less of the red is sent, and a little of the other colors mixed together is also sent; and so on, a little less and a little less of the red, and a little more and a little more of the others, till at the edge all the colors are reflected so as to make it look white.

[Sidenote: In what sense colors are said to come from the sap.]

In Part First I told you that the colors of flowers are made out of the sap, and now in this chapter I have told you that the colors are really made from the light. It may seem to you that both of these things can not be true; but while the colors are made from the light, in one sense they may also be said to be made from the sap. The flowers are so made out of the sap that they reflect the right colors from the light that comes to them. Thus a blue flower is so made as to reflect the blue part of the light. It is just as blue cloth is fitted by the dye that it is put into to reflect blue; and as we say that the dyer makes the cloth blue by his dye, so we say that the flower is made blue from the sap.

[Sidenote: Colors of leaves in autumn.]

I have told you in Part First about the change of color in the leaves in the autumn. All the summer the leaves send the green part of the light to your eyes; but when autumn comes there is some change made in them, so that some kinds of leaves reflect the red part of the light, some the yellow, some the orange, etc.

I have told you about the great variety of colors in the plumage of birds and in the coverings of insects. This variety is all owing to the different ways in which the light is reflected. Some reflect one of the seven colors of the light, and others some other color. Some that reflect all the colors of the light are white, as the swan; and some that reflect none of them look black, as the crow.

[Sidenote: Colors of clouds.]

Some of the most splendid displays of colors that can be witnessed we occasionally see in the clouds at morning or evening. Now all this is caused by nothing but sunlight and water, for you know that the clouds are made up of water in the shape of fog. The light, as we may say, paints these gorgeous colors upon the drops of water as they hang in the air. The reason that we see these displays of colors in the clouds only at morning and evening is, that the light from the sun strikes them in the right way then. It strikes them in such a way that some of the colors are reflected to our eyes, while others are not. The most common color reflected to our eyes by the clouds is red.

[Sidenote: Play of colors in changeable silks, ice, &c.]

[Sidenote: When and how the rainbow is formed.]

You can see in other things that the color of a thing depends on the way in which the light strikes it, and is reflected to your eyes. You see this in the changeable silk. As you move it, the light strikes it differently, and so different colors are reflected to your eyes. When you see the ice scattered on the ground from the trees in winter, shining in the bright sun, you see in one direction all the colors of the rainbow sparkling from the millions of pieces of ice; but if you look in the opposite direction you see none of these colors, but the ice looks white. Why is this? It is because the light on one side of you strikes the ice and is reflected differently from what it is on the other side. And you know that it is not after every thunder-shower that you see a rainbow. The light must strike the rain, and be reflected to your eyes in a particular way, in order to let you see the light divided up in the rain into its seven colors in the bow. You never see a rainbow if the rain is in the same direction with the sun. If the sun is in the west, the rain must be in the east to have the bow form; so that you are between the sun and the rain, with your back to the sun, as you see the bow. Sometimes a rainbow is seen in the morning, when a cloud comes from the east and it clears off by the cloud’s passing to the west. But this seldom happens, and the rainbow is commonly seen in the latter part of the day, the cloud coming from the west and passing off to the east.

_Questions._--What is the color of a thing? Does the dyer make color? What does he do? What is said about changeable silk? Mention some other things in which we see the colors change. What is said about the changes of color in different kinds of light? How are the different colors of flowers made? How is it when there are different colors in the same flower? What is said about the shading off of colors? In what sense are the colors of flowers made from the light? And in what sense are they made from the sap? What is said about the change of color in leaves in autumn? What is said about the colors of birds and insects? Tell about the colors of the clouds. Why do we see them at morning and evening? What is said about the way in which light strikes a thing and is reflected to our eyes? Where and in what part of the day do you commonly see the rainbow? Explain this.