the inside of the gland by the very thin walls of the capillaries and of the gland, and by this means, as in the air-sacs of the lungs, an exchange is permitted between the contents of the blood and of the air. Hence it will be seen that there is a strong resemblance between the structure and function of the skin and lungs, and an arrangement similar in principle exists in the kidneys.
Sweat contains in itself fatty matters even when freed from the excretion of the sebaceous glands, but when it reaches the skin it mixes with the oily products of these, and also with the little scales which are given off constantly from the surface of the scarf-skin.
It is well known that one of the chief causes, if not the chief cause, of skin disease is dirt, and that dirt which is the most injurious is this mixture of the excretions from the skin itself when left on its surface.
A dirty skin is a splendid garden in which parasites, both animal and vegetable, may grow and multiply.
Many of those brown stains met with between the shoulders and on the back, are due to a form of vegetable fungus which grows among the scales of the epidermis, and may soon be removed by soap and water. The disease called "ring-worm" is another sort of vegetable fungus, encouraged by similar conditions.
A daily bath all over is one of the most important preservers of health, and soap is a necessary adjunct to the bath, as without it the excretion
