Disorders Affecting the Color of the Skin.

Colored Patches. Maculoe. The depth of color in the skin depends on the amount of a certain coloring matter, called pigment, incorporated with the deeper and softer portion of the scarfskin. In the scarfskin of the inhabitants of northern latitudes, there is but little of this pigment; in that of the dwellers of Africa, there is a great deal; among the inhabitants of Southern Europe, the quantity is intermediate between the two.
The depth of color in the skin depends on the energy of its action. In the tropics, where light and beat are in excess, the skin is stimulated to great action, just as vegetation is, and the color is increased and intensified. This is illustrated every year before our eyes. In summer, under the heat of the sun and the flood of light,. the pigment forming power is increased, and the fairest skin is browned; while the withdrawal of these forces leaves the winter's scarf without pigment, and blanched.
What the sun and light do, under natural circumstances, diseased action may effect. Hence we occasionally meet with alterations of color in the skin, from a disordered state of the system. We witness the formation of patches of dark color and irregular shape on various parts of the body. Sometimes they are raised above the level of the skin, and are called moles. At other times, they have no elevation, and spread over the whole body.
Occasionally, from some peculiarity of constitution, the pigment is diminished, and white patches appear all over the body. At other times, a black person will become completely white. Such are called albinos.
In many cases the coloring of the skin has varieties of tint, as when persons of light complexion, are, in the summer season, covered with yellow spots, like stains. These spots are known by the name of .freckle., or, in learned language, lentigo.

Treatment. It is generally best not to meddle with a mole. If it be very unsightly, let it be removed by two incisions, taking out an elliptical portion of skin, and closing the wound with sticking plaster. In the case of bleached places, apply the shower bath, toilets, and a stimulating liniment (163) to the faded spots. For the change of color called sunburn, a liniment (191) of limewater, etc., is the best preparation. For freckles, use recipe 360, or, perhaps, still better, 864.