i98 Otservaiions on Colours. 
portion of two simple colours makes the exact intermediate oné, 
as of yellow and blue makes a green ; but another equal portion 
of the third simple colour, as red, neutralizes the whole, making 
it a gray, light or dark, according as the colours employed are 
light or dark. If only a small quantity of the third colour be 
used, it breaks the tint, making it approach more to a neutral 
tirit, according to the quantity used. By neutral tint, I do not 
mean the tint so called by landscape painters, which is inclined 
to blue and sometimes to purple, and ought rather to be called 
an aérial tint; but I mean by it, that negative gradation between 
white and black, which is best given by Indian ink. 
A mixture of two intermediate colours will produce a broken 
tint of the colour which lies between them in the figure; for in= 
stance, green and orange wil] produce a broken yellow ; green 
-and purple, a broken blue; and purple and orange, a broken red ; 
as may be accounted for thus: Green is one part blue and one 
part yellow, orange is one part yellow and one part red: thus, in 
the whole, when mixed together, there are two parts yellow, one 
part red, and one part blue: the red and blue and one part of 
the yellow would produce a neutral tint ; but the additional por- 
tion of yellow gives a tinge to the whole, and produces a broken 
or brown yellow. 
The effect of the three intermediate colours mixed together 
will be the same as the three simple ones, that is, they will pro- 
duce a gray or neutral tint of a depth proportionate to the 
strength of the colours employed, which will be evident on con- 
sidering them. It will be unnecessary to say further, that equal 
portions of all the colours, simple and intermediate, will still pro- 
duce a neutral tint, as will be evident from what is shown al- 
ready. 
The figure shows at once what colour or tint will neutralise 
another, they being directly opposite in the circle. Thus, op- 
pesite to yellow stands purple, which used in a proportion of two 
to one will neutralise the yellow ; opposite to green stands red, 
which will neutralise one the other; and so on with the whole 
circle. I have hitherto considéred only those proportions in the 
mixtures which produce a neutral colour; but by varying the 
quantities of the opposite or neutralising tint, when mixed with 
the different colours in the circle, all the variety of what are called 
ternary compounds may be produced: thus, a small portion of 
blue mixed with orange produces brown orange, the tint of 
which may be varied by more or less of the blue into a great 
number of different shades, all of which will still belong to the 
orange so long as, that colour predominates. Ifthe next per- 
ceptible variation from orange towards red be taken and mixed- 
with 
