Before discussing the importance of the rediscovery, let us turn back to the other use of that word values. If you remember, the word is used not only of the differences in degree in tint of some one color; for example, the different values of black, of green, of red and so on, but it is also used as a standard to compare a color of one hue with a color of another hue. Let me remind you of that Dutch treat picnic to which everybody brought a contribution of equal value. I need not tell you that the ten cents’ worth of soda crackers will make a bigger parcel than the ten cents’ worth of cheese, while ten cents’ worth of----’s “fine chocolate” would make a very small parcel indeed. Now, colors differ in the same way. All colors throw off a certain quantity of light, but the amount varies.