therefore conforms to the demands of our theoretical division.  Here, then, is something reasonably certain, certainly reasonable, and may serve as an hypothesis to be confirmed or confuted by subsequent research.  Coming now finally to the consideration of the musical parallel, let us divide a color scale of twelve steps or semi-tones into three groups; each group, graphically portrayed, subtending one-third of the arc of a circle.  The first or red group will be related to the physical nature, and will consist of purple-red, red, red-orange, and orange.  The second, or green group will be related to the emotional nature, and will consist of yellow, yellow-green, green, and green-blue.  The third, or blue group will be related to the intellectual and spiritual nature, and will consist of blue, blue-violet, violet and purple.  The merging of purple into purple-red will then correspond to the meeting place of the highest with the lowest, “spirit” and “matter.”  We conceive of this meeting-place symbolically as the “heart”—­the vital centre.  Now “sanguine” is the appropriate name associated with the color of the blood—­a color between purple and purple-red.  It is logical, therefore, to regard this point in our color-scale as its tonic—­“middle C”—­though each color, just as in music each note, is itself the tonic of a scale of its own.

Mr. Louis Wilson—­the author of the above “ophthalmic color scale” makes the same affiliation between sanguine, or blood color, and middle C, led thereto by scientific reasons entirely unassociated with symbolism.  He has omitted orange-yellow and violet-purple; this makes the scale conform more exactly with the diatonic scale of two tetra-chords; it also gives a greater range of purples, a color indispensable to the artist.  Moreover, in the scale as it stands, each color is exactly opposite its true spectral complementary.

The color scale being thus established and broadly divided, the next step is to find how well it justifies itself in practice.  The most direct way would be to translate the musical chords recognized and dealt with in the science of harmony into their corresponding color combinations.

For the benefit of such readers as have no knowledge of musical harmony it should be said that the entire science of harmony is based upon the triad, or chord of three notes, and that there are various kinds of triads:  the major, the minor, the augmented, the diminished, and the altered.  The major triad consists of the first note of the diatonic scale, or tonic; its third, and its fifth.  The minor triad differs from the major only in that the second member is lowered a semi-tone.  The augmented triad differs from the major only in that the third member is raised a semi-tone.  The diminished triad differs from the minor only in that the third member is lowered a semi-tone.  The altered triad is a chord different by a semi-tone from any of the above.