The use of the scarf skin is manifestly to protect the more delicate true skin, while at the same time it allows the waste products and used-up material to escape from the body. In the substance of the true skin are thousands of minute little bodies called papillae, which are specially concerned in the sense of touch, for the vast majority of these papillae contain the end of a small nerve. The numberless fine ridges seen on the palmar surface of the hands and fingers, and on the soles of the feet, are really rows of these papillae, covered of course by the layers of the outer skin. The supply of blood to the skin is also very plenteous, each of its innumerable papillae being abundantly supplied in this respect. As a proof of the amount of blood circulating within the skin, and of its extensive nerve supply, it is only necessary to mention the fact that the finest needle cannot be passed into it without drawing blood and inflicting-pain. In addition to the foregoing the skin also contains a countless number of very fine tubes, which penetrate through its layers and open on its surfaces by minute openings called pores. There are altogether three different varieties of these tubes distributed throughout the skin, namely, those intended for perspiration; secondly, those which lead from the oil glands; and lastly, those which enclose each hair of the body. The first of these, which carry away the perspiration from the body, are very fine, the end away from the surface being coiled up in such a way as to form a ball or oval-shaped body, constituting the perspiration gland. The tube itself is also twisted like a corkscrew, and widens at its mouth. It is estimated that there are between 2,000 and 3,000 of these perspiration tubes in every square inch of the skin. Now, as we have already seen, the external skin of an ordinary adult is equal to an area of about twelve square feet, and in a tall person it may be as much as eighteen square feet. The number of these tubes, therefore, in the whole body will be many hundreds of thousands, so that it will readily be seen how exceedingly important it is that they should be kept in thorough working order by cleanliness. The two great purposes fulfilled by the perspiration are the removal by its means of worn-out or effete material which is injurious to the system, and the regulation of the heat of the body by its influence. When it is stopped by any reason, such as catarrh or disease, the skin fails in its work, and the noxious matters, instead of being expelled from the body, are thrown back into the system. Hence there is a good deal of truth in the belief that a freely acting skin is always a safeguard against disease.