37 
that it will make a difference in regard to the compounds, which, under that 
change, will not all fall alternately in that arrangement*but that is not ma¬ 
terial to their situation in a picture. I scarcely need repeat that these colours 
belong to the first mass, or most prominent part of a picture. 
I come now to those fit for a secondary mass, the most brilliant of which 
are formed as follows, and form the first link in the gradation from pure to 
obscure colours. It has been shewn, that two colours contiguous to an in¬ 
termediate one, will form an imitation of that colour; so will a mixture of 
two compound colours produce an imitation of a pure prismatic r one, thoug 1 
verv far inferior in brilliancy, but still not the less useful to a painter. Again, 
these secondary pure colours, that is, yellow, red, violet, and blue, will orm, 
by mixture, secondary compound ones, orange, indigo, and green; and these 
secondary compounds will form, by mixture, pure tints of a third order and 
these a-ain compounds as before; so that supposing a picture consists of 
three distances, you have a distinct set of colours for each, the formation of 
which is set down in the following tables, and they may all be made lighter or 
darker by the addition of white or black. An infinite number of other 
compound tints may be formed out of these three different tables, by varying 
the mixtures and the proportions; but to give tables of them also would lead 
me into so wide a field that it would take me beyond the bounds I prescribed 
to myself, and further, perhaps, than those into whose hands this wr 
would be inclined to follow me. But should any one choose to pursue these 
trials I refer them to Mr. Gal ton’s Experiments on Colours, and to Mr. 
Harris’s System of Colours : in the latter they will see the whole range of pure, 
and compound colours, and the contrasting tints to each, at one view. 
* Though even there every intermediate tint may be formed by the two contiguous ones. 
\im 
