2. Color is an internal sensation originating in the excitation of the optic nerve by a wave action which we call light.
3. The theory of light, the wave theory, is based upon the assumption that throughout all space there is an infinitely thin medium called ether. Scientists differ as to what this may be, but its movements constitute light, a reflection from a luminous body.
4. Everything which we see is visible because it either emits light, like a flame, or reflects light.
5. A piece of black cloth upon a white plate reflects but a small proportion of the light. The plate reflects a large proportion. A piece of black velvet reflects less light than black cloth and gives the effect of absolute blackness, or an empty and dark space.
6. In practical demonstrations the study of color will be confusing unless it is understood at the outstart that pure prismatic colors can seldom be found in manufactured pigments, hence any demonstration of the theory of color composition is usually unsatisfactory.
7. The theory which brings out of a ray of sunshine the disunited prismatic colors carries with it the deduction that before separation these colors constitute white light; but it must be manifest to even the superficial reader that such colors are mere spectrum colors—vision colors—and any amalgamation of material or pigment colors, so far from producing white, produces almost black.