OF ARTS AND SCIENCES. 



227 



Notes. — In the case of red paper the whole of the screen is slightly 

 colored red, but the spot is principally colored. The other side i« 

 colored pale green, which deepens as the red grows stronger. 



Yellow Paper. 



Notes. — The spot is colored yellow on one side, and pearl on the 

 other. The contrast decreases as the distance from the paper in- 

 creases. 



The general results are as follows : — 



White 2409 



Yellow 2070 



Green 1810 



Red 1551 



Silvered Mirror (Face). 



Ratios. Averages. 

 IJ Mt.*,(D 



