COLOR 99 



farther they ascend into the air, the darker the sky becomes. 

 If the air were absolutely pure, we would have a black sky. 



References : 



1. 1103 : 170-171. Colors of the Sky. 



2. 1304 : 233. The Cause of Colors. 



3. 1601:7. Color. 



4. 1803 : 443-450. Color Phenomena. 



a. 1305 : 103-105. Color of the Atmosphere. 



6. 1801:238-241. Color. 



c. 1802 : 258-260. Color Color Sensation. 



d. 1804:386-391. Color. 



e. 1805:244-247. Color. 



/. 1807 : 322-332. Dispersion and Color. 



g. 1808:418-421. Color. 



h. 1811:214-220. Cause of Color. 



Experiment 35. Color. 



Apparatus : Alcohol or gas lamp, asbestos paper to fit lamp 

 as a collar, pieces of cloth colored red, yellow, and blue, beaker 

 250 c.c. 



Materials : Common salt, soap, -solution of rosin in alcohol, 

 (one part rosin, ten parts alcohol). 



a. Dip asbestos paper in saturated solution of salt, and 

 fasten around burner. Then light burner and darken room. 

 Hold the piece of cloth near the flame. What color is the red 

 now? The yellow? The blue? Conclusions? Notice the 

 color of the faces of your companions. Are the faces rosy ? 

 Does color belong to an object itself? 



b. Fill beaker with water, and add a drop or two of the rosin 

 solution. The rosin is insoluble in water and is suspended in 

 very fine particles. What color is the water by reflected 

 light ? By light which has passed through the water, that is, 

 transmitted light ? Add more rosin and state results. What is 

 the connection between this experiment and the color of the sky ? 



