25 jl BRAMBLES A^D BAY LEAVES. 
of the rays are dependent on a fixed law of their variable 
refrangibility. Suppose the angle of the violet ray to be 
40° 17', then the angle of the red will be 42° 2', and 
the difference between them will be the breadth of the bow, 
or 1° 45'. So, if we suppose the bow to be divided in 
breadth into 360 equal parts, the red will occupy 45 
parts, and the violet 80 ; the orange 27, and the indigo 
40; the yellow 48, and the blue 60; and mid-way between 
them will be the green, consisting of 60 parts. So far 
as I know, it has never been observed that these propor¬ 
tions are exactly adapted to the capacity of the human 
eye for the distinguishing of colours. These are, in 
fact, just the proportions in which a flower-bed should be 
planted, or a coloured frieze arranged, to tell with best 
effect as a pictorial harmony. The violet and indigo are 
the least attractive to the eye, and they have a breadth of 
80 and 40, respectively; the yellow and orange are the 
most attractive, and they have a breadth of 48 and 27; 
orange, moreover, is the most garish of colours, and, if 
injudiciously used in artificial colouring, gives a vulgar 
tone to the picture. Here observe, it is subordinate to 
the group of colder tints, and has the least space of all. 
Green, on which the eye always rests with complacency, 
has a breadth of 60, enough to satisfy and harmonize the 
colours of opposite classes on each side of it; and that 
it may not obliterate by unhappy juxtaposition the blue 
which joins it on the violet side, the blue has an equal 
breadth, and cannot be dismissed by the most casual 
observer. Mark, lastly, that the warm rays on the red 
side of the green have an aggregate breadth of 120, and 
the cold rays a breadth of 180—a system of compensations 
