Page:Proceedings of the Royal Society of London Vol 69.djvu/62

54 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).

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