blage in a sphere by the three qualities of
HUE, VALUE, and CHROMA. It will aid the memory to call the thumb of the
left hand RED, the forefinger YELLOW, the middle finger GREEN, the ring
finger BLUE, and the little finger PURPLE (Fig. 6). When the finger tips
are in a circle, they represent a circuit of hues, which has neither
beginning nor end, for we can start with any finger and trace a sequence
forward or backward. Now close the tips together for white, and imagine
that the five strong hues have slipped down to the knuckles, where they
stand for the equator of the color Sphere. Still lower down at the wrist
is black.

(55) The hand thus becomes a color holder, with white at the finger
tips, black at the wrist, strong colors around the outside, and weaker
colors within the hollow. Each finger is a scale of its own color, with
white above and black below, while the graying of all the hues is traced
by imaginary lines which meet in the middle of the hand. Thus a child's
hand may be his substitute for the color sphere, and also make him
realize that it is filled with grayer degrees of the outside colors, all
of which melt into gray in the centre.

+Neighborly and opposite hues; and their mixture.+

(56) Let this circle (Fig. 7) stand for the equator of the color sphere
with the five principal hues (written by their initials R, Y, G, B,
and P) spaced evenly about it. Some colors are neighbors, as red and
yellow, while others are opposites. As soon as a child experiments with
paints, he will notice the different results obtained by mixing them.

[Illustration: Fig. 7.]

First, the neighbors, that is, any pair which lie next one another, as
red and yellow, will unite to make a hue which retains a suggestion of
both. It is _intermediate_ between red and yellow, and we call it
YELLOW-RED.[17]

(57) Green and yellow unite to form GREEN-YELLOW, blue and green make
BLUE-GREEN, and so on with each succeeding pair. These intermediates are
to be written by their initials, and inserted in their proper place
between the principal hues. It is as if an orange (paragraph 9) were
split into ten sectors instead of five, with red, yellow, green, blue,
and purple as alternate sectors, while half of each adjoining color pair
were united to form the sector between them. The original order of five
hues is in no wise disturbed, but linked together by five intermediate
steps.

(58) Here is a table of the intermediates made by mixin