226 PROCEEDINGS OF THE AMERICAN ACADEMY 



Percentage of Total Light reflected from Colored Papers. 

 Green. 



Notes. — The spot is colored green on one side by reflection from 

 the paper. The intensity of the color increases with the decrease of 

 the distance from the paper. The other side of the spot is colored 

 pink, which also varies with the distance from the paper, becoming 

 white as the distance increases, and more distinctly pink as the dis- 

 tance decreases. The spot alone is colored. The coloring matter of 

 this paper was found to be arsenic. 



