PRINCIPLES OF COLOR. 
25 
The scope of the present work will not allow an ex- 
tended dissertation on this subject, the aim being to fur- 
nish the student with a convenient means of identifying 
or determining those colors regarding which he may be 
more or less uncertain. It is obviously impracticable to 
illustrate all the numerous hues, shades, and tints which 
occur in the plumage of birds ; but it is believed that the 
carefully selected assortment depicted on plates II. to X. 
will answer every reasonable requirement. A great diffi- 
culty has been encountered in the arrangement of the 
colors on the plates, from the circumstance that a linear 
series, which shall express all the relations, gradations, and 
transitions, is here quite as impossible as in zoological or 
botanical classifications. Thus, all the purples have more 
or less of blue and red in their composition ; but some of 
them through the admixture of yellow or gray (black and 
white) tend more or less toward brown or gray ; any other 
series of compound colors presenting equally perplexing 
the light ; which is unfortunate, since in this color we have almost the 
exact red of the solar spectrum, and can therefore produce by its combina- 
tion with the purest yellow (light cadmium) and blue (ultramarine), 
purer orange and purple tints than can be obtained by the use of any 
other red. Genuine ultramarine is said to be the most perfect of known 
pigments, and the same may be said of the lighter cadmium-yellows ; so 
that the great desideratum is a perfect red. Among trustworthy pigments, 
vermilion, Paris green, and ultramarine are named by Von Bezold (p. 136) 
as those which most nearly represent the primary colors. However, while 
the two latter are probably as pure as it will be possible to obtain, the 
first is very far from a perfect red, making neither a pure orange with 
yellow nor a purple with any blue. 
Speaking of, this matter, a writer in the " Art Union" (we make the 
quotation at second hand, from the "Art Interchange," vol. xii. no. 13, 
p. 148) makes the following observations: "We have a good supply of 
yellows of every shade, some of them quite durable ; we are pretty well 
furnished with blues, but good reds are very few. The reds of iron 
[Venetian red, light red, etc.] are too dull, the madder preparations are 
too weak. Vermilion is excellent in its place, but there is absolutely 
no true red of good body and quite durable." 
