[Illustration: Fig. 57.] Fig. 57 is a very highly magnified portion of the skin. The layer marked 1 is the outside, very thin skin, called the _cuticle_ or _scarf skin_. This consists of transparent layers of minute cells, which are constantly decaying and being renewed, and the white scurf that passes from the skin to the clothing is a decayed portion of these cells. This part of the skin has neither nerves nor blood-vessels. The dark layer, marked 2, 7, 8, is that portion of the true skin which gives the external color marking diverse races. In the portion of the dark layer marked 3, 4, is seen a network of nerves which run from two branches of the nervous trunks coming from the spinal marrow. These arc nerves of sensation, by which the sense of touch or feeling is performed. Fig. 58 represents the blood-vessels, (intermingled with the nerves of the skin,) which divide into minute capillaries that act like the capillaries of the lungs, taking oxygen from the air, and giving out carbonic acid. At _a_, and _b_ are seen the roots of two hairs, which abound in certain parts of the skin, and are nourished by the blood of the capillaries. [Illustration: Fig. 58.] [Illustration: Fig. 59.] At Fig. 59 is a magnified view of another set of vessels, called the lymphatics or absorbents. These are extremely minute vessels that interlace with the nerves and blood-vessels of the skin. Their office is to aid in collecting the useless, injurious, or decayed matter, and carry it to certain reservoirs, from which it passes into some of the large veins, to be thrown out through the lungs, bowels, kidneys, or skin. These _absorbent_ or _lymphatic_; vessels have mouths opening on the surface of the true skin, and, though covered by the cuticle, they can absorb both liquids and solids that are placed in close contact with the skin. In proof of this, one of the main trunks of the lymphatics in the hand can be cut off from all communication with other portions, and tied up: and if the hand is immersed in milk a given time, it will be found that the milk has been, absorbed through the cuticle and fills the lymphatics. In this way, long-continued blisters on the skin will introduce the blistering matter into the blood through the absorbents, and then the kidneys will take it up from the blood passing through them to carry it out of the body, and thus become irritated and inflamed by it. [Illustration: Fig. 60]