54 Dr. E. S. Clay. On the Application of 



No. 9) had no very great absorption anywhere. The blue ink (Curve 

 No. 10) was not transparent enough anywhere, especially in the 

 green. 



In another set of inks printed by Mr. Gamble the blue (Curve 

 No. 14) had very much the character of the first one above, as had also 

 the pink and yellow (Nos. 15 and 18). 



8 l 16 SO 4 ea 3a S6 4O 4^- 46 6 66 60 64 



Scale readings. 



The White against White Curves show the effect of the film of moisture on 

 the prism, on different dates. 



Mr. Gamble formed a Red by printing both the pink and yellow 

 inks on the same paper, and it is interesting to compare the absorptions 



