Howard, Frank: Colour, as a means of art: being an adaptation of the experience of professors to the practice of amateurs (London, 1838)

24 HARMONY.

other fluid, as are sounds, the Harmony of Colours
may equally become the subject of mathematical
calculation, with equally certain results; at present
we cannot go beyond rude approximations by guess
or supposition; and are vaguely placed under the
regulation of Taste, itself as Protean and undefined

The theory of the three or seven colours being
all equally necessary to each other, which has been
derived from the division of the ray of light by a
prism, has been supposed to afford the relative
proportions of the various tints necessary to Har-
mony in a picture, because existing in light; and
fanciful, but entirely unfounded, analogies have
been drawn by enthusiasts between the seven colours
and the seven notes, and the three colours and the
notes of the common chord in music : but without
going into the question of how far this would be
likely to assist in our present enquiry, if true;
it may be sufficient to observe that these relative
proportions vary with the substance of the prism
by means of which the ray of light is divided ; so
that the whole induction falls to the ground.

But were the proportions always the same, the
induction would be equally untenable. For, though
light may be very beautiful; and the Rainbow
may be very beautiful; a totally different kind of