HOW COLOR IS AFFECTED BY THE KIND OF LIGHT 55 



circle and a blue one. By slipping one circle through the slit 

 of the other you can get portions of each color to show. Move 

 the two circles over each other so that % of the circle is blue 

 and J^ is yellow. Slip the combination circle on the top, and 

 fasten it to the cardboard by means of tiny tacks or thumb 

 tacks. Instead of tacks you can use a drop or two of paste. 

 Then spin the top. What color do you get? Remember that 

 gray is poorly illuminated white. 



d. Try a combination yellow-red circle; what is its color? A 

 red-blue circle. 



Make a circle out of the 3 colors : red, green, and blue, each of 

 them H of the circle. What color do they give? 



e. Try a black disk with a yellow one, using several different 

 proportions of the colors. Try black and red and black and 

 green, giving the results. 



EXERCISE 53 

 HOW COLOR IS AFFECTED BY THE KIND OF LIGHT 



Apparatus and Materials. Strip of blotting paper or asbestos paper, 

 saturated salt solution, Bunsen or alcohol burner, colored papers of 

 Exercise 52, lamp with a red globe (or paper soaked in strontium 

 chloride solution). 



a. Soak a strip of blotting paper or asbestos paper in a 

 saturated salt solution, and dry it on a radiator. Have the 

 room dark, and hold the prepared paper in a Bunsen or alcohol 

 flame. What is the color of the light given by the flame? 

 Examine the colored papers of Exercise 52 in this " sodium" 

 light. What .color has each one? 



b. Examine the colored papers in a red light. Get this 

 light from a lamp or lantern with a red globe, or cover a globe 

 with red crepe paper. What is the apparent color of each 

 paper? 



