Theory of Colours — trans. Charles Lock Eastlake (1840)

With the form, the colour also becomes changed, and a certain law regulates the general order of hues as well as that particular distribution by which a single feather becomes party coloured, It is from this that all combination of variegated plumage arises, and whence, at last, the eyes in the peacock's tail are produced. It is a result similar to that which we have already unfolded in treating of the metamorphosis of plants, and which we shall take an early opportunity to prove.

658.

Although time and circumstances compel us here to pass by this organic law, yet we are bound to refer to the chemical operations which commonly exhibit themselves in the tinting of feathers in a mode now sufficiently known to us.

659.

Plumage is of all colours, yet, on the whole, yellow deepening to red is commoner than blue.

660.

The operation of light on the feathers and their colours, is to be remarked in all cases. Thus, for example, the feathers on the breast of certain parrots, are strictly yellow; the scale-like anterior portion, which is acted on by the light, is deepened from yellow to red. The breast of such a bird appears bright-red, but if we blow into the feathers the yellow appears.

661.

The exposed portion of the feathers is in all cases very different from that which, in a quiet state, is covered; it is only the exposed portion, for instance, in ravens, which exhibits the iridescent appearance; the covered portion does not: from which indication, the feathers of the tail when ruffled together, may be at once placed in the natural order again.

LIV.

MAMMALIA AND HUMAN BEINGS.

662.

Here the elementary colours begin to leave us altogether. We are arrived at the highest degree of the scale, and shall not dwell on its characteristics long.

663.

An animal of this class is distinguished among the examples of organised being. Every thing that exhibits itself about him is living. Of the internal structure we do not speak, but confine ourselves briefly to the surface. The hairs are already distinguished from feathers, inasmuch as they belong more to the skin, inasmuch as they are simple, thread-like, not branched. They are however, like feathers, shorter, longer, softer, and firmer, colourless or coloured, and all this in conformity to laws which might be defined.

664.

White and black, yellow, yellow-red and brown, alternate in various modifications, but they never appear in such a state as to remind us of the elementary hues. On the contrary, they are all broken colours subdued by organic concoction, and thus denote, more or less, the perfection of life in the being they belong to.

665.

One of the most important considerations connected with morphology, so far as it relates to surfaces, is this, that even in quadrupeds the spots of the skin have a relation with the parts underneath them. Capriciously as nature here appears, on a hasty examination, to operate, she nevertheless consistently observes a secret law. The development and application of this, it is true, are reserved only for accurate and careful investigation and sincere co-operation.

666.

If in some animals portions appear variegated with positive colours, this of itself shows how far such creatures are removed from a perfect organisation; for, it may be said, the nobler a creature is, the more all the mere material of which he is composed, is disguised by being wrought together; the more essentially his surface corresponds with the internal organisation, the less can it exhibit the elementary colours. Where all tends to make up a perfect whole, any detached specific developments cannot take place.

667.

Of man we have little to say, for he is entirely distinct from the general physiological results of which we now treat. So much in this case is in affinity with the internal structure, that the surface can only be sparingly endowed.

668.

When we consider that brutes are rather encumbered than advantageously provided with intercutaneous muscles; when we see that much that is superfluous tends to the surface, as, for instance, large ears and tails, as well as hair, manes, tufts; we see that nature, in such cases, had much to give away and to lavish.

669.

On the contrary, the general surface of the human form is smooth and clean, and thus in the most perfect examples, the beautiful forms are apparent; for it may be remarked in passing, that a superfluity of hair on the chest, arms, and lower limbs, rather indicates weakness than strength. Poets only have sometimes been induced, probably by the example of the ferine nature, so strong in other respects, to extol similar attributes in their rough heroes.

670.

But we have here chiefly to speak of colour, and observe that the colour of the human skin, in all its varieties, is never an elementary colour, but presents, by means of organic concoction, a highly complicated result.--Note X.

671.