and these are called tertiaries. After having accepted this fiction as a, scientific theory for so many years, it is very difficult to convince the artists and colorists that in it all there is nothing of value to any one, but such is practically a fact, because from no three pigmentary effects in red, yellow and blue can the three colors orange, green and purple of corresponding purity be produced, neither are the primary colors complementary to the secondaries as claimed nor are the so-called tertiaries new and distinct colors but simply gray spectrum colors. Because the red, yellow and blue theory would not stand the test of scientific investigation the Young-Helmholtz theory of three other primaries red, green and violet, has been quite generally adopted by the scientists of the past generation.
All these discussions of the scientists are intensely interesting and no doubt of great importance in the line to which they pertain, but practically neither the artists nor the primary school teachers care for all these theories and discussions and because the scientists have closely confined themselves to these lines, the artists and teachers have seen nothing of value to them in their theories.
In going to the solar spectrum for standards on which to base pigmentary standards, we have given little attention to these various theories in their details, but the one fact of science has received careful attention, namely, that all color effects in nature and art are produced by light reflected from material surfaces. Therefore, inasmuch as the light reflected from any surface must be affected by both the material color of the surface and the color of the light which illuminates the surface, it is necessary that every one having to do with this subject be informed as to what color must be expected to result from given conditions.
In order that this phase of the subject be discussed and thus more fully understood, there must be a terminology or nomenclature in which to express the results produced by given con-
