It is not an unimportant lesson for children to learn, that the same things seem different in different circumstances. The fact that white light is composed of different colored rays can be illustrated by giving the children prisms to hold up in the sunshine; and by calling their attention to the splendid colors of the sky at sunset and sunrise, when the clouds act as prisms, and to the rainbow. Children of the Kindergarten age, will be so much engaged with the beautiful phenomenon, they will not be likely to ask questions as to how the light is separated by the prism and clouds; they will rest in the fact. But if, by chance, analytic reflection has supervened, and they do, then a large ball on which all the six colors are arranged in lines meridian-wise, to which a string is attached at one pole, or both poles, can be given them, and they be told to whirl it very swiftly. This will present the phenomenon of the merging of the colors to the eye by motion, so that the ball looks whitish from which you can proceed to speak of light as being composed of multitudinous little balls, of the colors of the rainbow, in motion, and so looking white.
If some uncommon little investigator should persist to ask why things seem to be other than they are, he must be plainly told, that the reason is in something about his eyes, which he cannot understand now, but will learn by and by, when he goes to school and learns _optics_.
Children are only to be _entertained_ in the Kindergarten, with the facts of nature that develop the organs of perception, but a skillful teacher who reads Tyndall's charming books and the photographic journals, may bring into the later years of the Kindergarten period many pretty phenomena of light and colors, which shall increase the stock of facts, on which the scientific mind, when it shall be developed, may work, or which the future painter may make use of in his art.
When Allston painted his great picture of Uriel, whose background was the sun, he thought out carefully the means of producing the dazzling effect, and drew lines of all the rainbow colors in their order, side by side, after having put on his canvass a ground of the three primary colors mixed. When the picture was first exhibited at Somerset House, the effect was dazzling, and it was bought at once by Lord Egremont, in a transport of delight; and for twice the sum the artist put upon it, that is, six hundred guineas. I do not know whether time may not have dimmed its brilliancy, since paint is of the earth, earthy; but to paint the sun at high noon, and have it a success, even for a short time, is a great feat; and art, in this instance, took counsel of science deliberately, according to the artist's confession. But perfect sensuous impressions of color and its combinations, were the basis of both the science and the art.