ganic substance. Such is the brilliant paint, carmine, which is the pigment of the cochineal insect, and the red color of blood, which may be collected in crystals, separate from the other particles to which it is united.
Even the powder not unknown to ladies of fashion is one of Nature's beautifying means. That which is left on the hands of the ruthless boy, when he has caught a butterfly, is a common instance; but there are birds, such as the large white cockatoo, which leave a white powder on the hands. An African traveller speaks of his astonishment on a rainy day to see his hands reddened by the moist plumage of a bird he had just killed. The most ordinary way, however, in which the pigment is found is when it exists in the depths of the tissues reduced to very fine particles, best seen under the microscope. When scattered, they scarcely influence the shade; but, when close together, they are very perceptible. This explains the color of the negro: under the very delicate layer of skin which is raised by a slight burn there may be seen abundance of brown pigment in the black man. It is quite superficial, for the skin differs only from that of the European in tone; it wants the exquisite transparency of fair races. Among these, the colors which impress the eye do not come from a flat surface, but from the different depths of layers in the flesh. Hence the variety of rose and lily tints according as the blood circulates more or less freely; hence the blue veins, which give a false appearance, because the blood is red; but the skin thus dyes the deep tones which lie beneath it; tattooing with Indian-ink is blue, blue eyes owe their shade to the brown pigment which lines the other side of the iris, and the muscles seen under the skin produce the bluish tone well known to painters.
The chemical nature of pigment is little known; the sun evidently favors its development in red patches. Age takes it away from the hair when it turns white, the coloring-matter giving place to very small air-bubbles. The brilliant white of feathers is due to the air which fills them. Age, and domestic habits exchanged for a wild state, alter the appearance of many birds and animals; in some species the feathers and fur grow white every year before falling off and being renewed; as in the ermine, in spring the fur which is so valued assumes a yellow hue, and, after a few months, becomes white before winter.
It would, however, be an error to suppose that all the exquisite metallic shades which diaper the feathers of birds and the wings of butterflies arise from pigments; it was a dream of the alchemists to try to extract them. Their sole cause is the play of light, fugitive as the sparkles of the diamond. When the beautiful feathers on the breast of a humming-bird are examined under the microscope, it is astonishing to see none of the shades the mystery of which you would penetrate. They are simply made of a dark-brown opaque substance not unlike those of a black duck. There is, however, a remarkable arrangement; the barb of the feather, instead of being a fringed
