631. What is said of these tubes in the eyelids? In the ear? In the scalp? What are these glands sometimes called?
Observation. Among the inhabitants of cities, and especially in persons who have a torpid state of the skin, the contents of the oil-tubes become too dense and dry to escape in the usual manner. Thus it collects, distends the tube, and remains until removed by art. When this impacted matter reaches the surface, dust and smoke mix with it, then it is recognized by small, round, dark spots. These are seen on the forehead, nose, and other parts of the face. When this matter is pressed out, the tube gives it a cylindrical form. The parts around the distended tubes sometimes inflame. This constitutes the disease called, “ac´ne punc-ta´ta.”
632. The PERSPIRATORY APPARATUS consists of minute cylindrical tubes, which pass inward through the cuticle, and terminate in the deeper meshes of the cutis vera. In their course, each little tube forms a beautiful spiral coil; and, on arriving at its destination, coils upon itself in such a way as to constitute an oval-shaped, or globular ball, called the perspiratory gland.
633. The opening of the perspiratory tube on the surface of the cuticle, namely, “the pores,” is also deserving of attention. In consequence of its extremity being a section of a spirally-twisted tube, the aperture is oblique in direction, and possesses all the advantages of a valvular opening, preventing the ingress of foreign injurious substances to the interior of the tube and gland.
634. “To arrive at something like an estimate of the value of the perspiratory system, in relation to the rest of the organism, I counted the perspiratory pores on the palm of the hand, and found 3528 in a square inch. Now each of these pores being the aperture of a little tube about a quarter of an inch 292 long, it follows, that in a square inch of skin on the palm of the hand there exists a length of tube equal to 882 inches, or 73½ feet. Surely such an amount of drainage as seventy-three feet in every square inch of skin—assuming this to be the average for the whole body—is something wonderful and the thought naturally intrudes itself, What if this drainage be obstructed?
What is said of the retention of the unctuous matter in the oil-tubes? 632. Of what does the perspiratory apparatus consist? 633. What is peculiar in the opening of the perspiratory tubes on the surface of the cuticle? 634. How many perspiratory pores did Dr. Wilson count upon a square inch of skin on the palm of the hand?
Fig. 116.
