COLOURS OF FLOWERS. 
53 
colour which results from the omission of any one or more 
of the seven :—Let them be arranged as before, or let sectors 
answering to the breadths be marked off upon the circular disc of 
paper. Then, let any one be omitted ; and a diameter, drawn 
through the middle of its sector on the circumference and the 
centre of the circle, will cut the opposite circumference in the locus 
of the complemental colour, which may be either in the intensity 
of a single colour, or cn the confines where one blends with the 
another. If two colours which lie next to each other are omitted, 
a diameter through the middle of their two arcs and the centre 
will cut the opposite circumference in the colour which is comple¬ 
mental to the two ; and if the two are not proximate to each 
other, the complemental colour will still be found by drawing a 
diameter intermediate between the middles of their sectors. Upon 
this principle, if the blue is omitted, the diameter bisecting its 
sector, will meet the opposite circumference in the orange part of 
the red ; and so of the other colours, the complements of which 
may be found either by a diagram or by simple calculation. Thus, 
if we omit the yellow, the half of which is 24, we have the opposite 
extremity of the diameter upon the indigo, within 4 degrees of 
the violet; if we omit the orange, we have the complemental 
colour upon the green, near the verge of the blue ; if we omit 
the violet, we have the complemental colour upon the green, two- 
thirds from the yellow; and so of all the other colours. 
If the colours had been an even number, each occupying an 
equal extent of the spectrum, there would have been but one set 
of contrasts, and each pair of colours would have been reciprocally 
the complements of each other ; but the odd number and unequal 
extent of the colours give rise to a very great variety : and by 
this means we are not tied down to one single colour, as the means 
of relieving the eye from the fatigue of another, or rendering 
it keenly susceptible to its beauty, but can range through all 
colours, and find relief and beauty at every change. 
The accidental colour, as most agreeable to the eye, does not in 
all cases correspond with the mathematical complement. White 
and black, being the contrast of every colour with no colour at all, 
are constant, and have no accidentals but each other ; but none of 
the others reciprocate in pairs. Thus, green is the accidental 
colour of red; but red is the accidental colour of blue; while 
green is the accidental colour of purple. So also, blue, of which 
