The Dispersion of Light -Demonstration-Take a prism into a dark room and hold it in front of a horizontal slit in a shutter. When a beam of sunlight passes through the prism, it is not only refracted, but separated into a band of colors on the opposite wall.
This dispersion is due to the fact that the index of refraction in a glass prism varies with the wave length of the light. The spectrum formed is called the solar spectrum, and consists of a series of colors passing imperceptibly from violet, which is refracted the most, through indigo, blue, green, yellow, and orange, to red, which is refracted the least.
Demonstration. - Paste two narrow bands of paper, one violet and one red, upon a black card, and look at them through a prism. It will be seen that the red rays are refracted less than the violet.
