Charles. If we have got through with talking about the scarf-skin, I should like to ask about the next layer, for you told us there are three coats.
Father. Yes, there are three coats. Immediately beneath the scarf-skin, is what is called the mucous coat. The mucous coat is chiefly remarkable as the seat of the colouring matter of the skin.
Albert. Then I should think that persons of dark complexion must have much thicker mucous coats than those of light complexion.
Father. They have. It can scarcely be seen with those who are of a very light complexion, but in the negro it is thick. If the mucous coat were the same in all persons, all would be of one colour. The mucous coat is very bright in those fishes and other animals whose skins have beautiful, variegated colours, and is the cause of their brilliant appearance. The mucous coat, like the cuticle, is destitute of blood-vessels, and of very active nerves.
Albert. As it is not yet late, let us talk about the third layer, and then we shall have some idea of the composition of the skin.
Father. The third, or inmost layer, called the true skin, is much thicker than either of the other layers of the skin. The true skin seems to be a complete network of extremely small blood-vessels and nerves.
Charles. I can see that this is so; for I cannot prick entirely through the skin, even with the point of the finest needle, without giving some pain, and drawing some blood; and I suppose that the pain is caused by piercing a nerve, and the bleeding by opening a blood-vessel.
Father. You are right, my son. There are so many nerves in the true skin, that in amputating a limb, the principal pain is always in the skin.
Albert. I suppose we should not be able to distinguish different things by the touch, unless the true skin were furnished with nerves.
Father. One of the great uses of the skin is to remove from the body the impure matter which is constantly collecting. You both have, when warm, perceived drops of sweat, or perspiration, on your faces and other parts of your bodies. Much impure matter is removed in that way, which, if not removed, would be very injurious to the health.