2274. That which is reduced beneath the vitrified epidermis determines the colour of the skin. With a demi-oxydation it is uncoloured, appears white. Where the integument is thin, the red colour of the blood appears through it; such integument is therefore white upon the whole, but red in individual places.
2275. With the most complete reduction effected by the highest operation of light, its substratum or under-layer becomes black. The mucus passes over into reduced carbon. Beneath the vitreous epidermis there is thus a metallic pigmentary membrane.
Hairs.
2276. Capillary vessels, which simply convey mucus, but are elongated singly above and from out the cutis, are Hairs. The idea of the hair is a capillary vessel, the contents of which are no longer blood, but reduced mucus. It is an indifferent capillary vessel. The hair is hollow and contains an oil, which determines the colour.
2277. In the hairs the nutritive system is prolonged above the body.
2278. The hairs and scales are the general terrestrial system of the body determined by the air.
2279. Thus the earth has sprung up into a plant. Scales and hairs are like true vegetable leaves, which still continue their process in the animal; they can no longer it is true make their respiratory process hold good for the animal process itself, but are at present content with only oxydizing the material of evaporation. It is properly the integument only, not the entire body, which respires through hairs and scales.
2280. The hairs are dried branchial filaments, and therefore continue to occupy in Man, those situations only where in the lower animals branchiæ or tentacula are placed. Around e. g. the mouth, upon the head, under the arms or in the axillæ, and around the sexual apertures.
2281. The feathers are dried ramified branchiæ, pinnate leaves.
2282. The hairs participate in the electric process of the whole body.