Is the color of any object changed by falling upon a looking-glass? No; the color of every object is reflected from a looking-glass without change. Do other objects generally reflect the colors falling upon them? They do not; they absorb or hide the color of all other objects, and reflect only their own color. If every object was a good reflector of color, like a looking-glass, what would result? Then every object would reflect the color of every other object around it, and there would be an endless confusion of colors. What objects reflect the most light? Those of a white or light color. What objects reflect the least light? Those of a darker color; and the nearer the color approaches to black, the less light it reflects. Why is it darker when the sky is covered by dark-colored, than by light-colored, clouds? Because the dark-colored clouds reflect less light, than the light-colored clouds do. What advantage do we derive from the green color of the grass and the leaves? They reflect a soft, pleasant light, which does not dazzle or hurt our eyes. How would it be if those objects were white? They would dazzle us by the amount of light reflected. If we wish to make a room light, of what color should the walls be? They should be white; and when papered, it should be with light-colored paper. Why does dark-colored paper darken a room? Because it absorbs some of the rays of light which come in at the windows; hence, there is less light in the room. Dark-colored carpets, or dark furniture, darken the room for the same reason. Does the light from a burning body differ from sun-light? Yes; it differs in intensity, in color, and in many other ways. What effect does the lamp-light have upon the color of some substances? It changes their color. Where may we find an example of this? In trying to match the colors of thread or silk at night. Why is the color different by lamp-light from what it is by daylight? Because the yellow color of the lamp’s rays acts upon the color of the silk, forming a third color. Blue silk becomes green by lamp-light, and red silk becomes orange. Are all persons able to distinguish one color from another? No; some are color-blind. To such persons all colors appear to be alike. What curious instances of color-blindness may be mentioned? Dr. Mitchell tells of an officer who bought a blue coat and a red waistcoat, thinking them to be of the same color. He also tells of a tailor who patched a black waistcoat with a piece of crimson; and of another, who put a red collar on a blue coat. Dr. Dalton lost a piece of red sealing-wax in the grass, and he could not find it because it and the grass seemed of the same color to him. Refraction of Light. How do the rays of light from the sun come to us? They come to us in straight lines. When the rays of light pass from one substance to another more dense, what takes place?