These three organs are in close relation to each other, for when one is threatened the others come to its assistance and aid it in the work of elimination. Thus, when the kidneys are not functionating as they should, the skin comes to the rescue and helps to eliminate a large part of the remaining products by increased perspiration. Nature often does this spontaneously before we come to her aid. The intestines will do their best, in like manner, to expel a part of these products. Recognizing this co-operative action of almighty Nature, we must also try to be of assistance by careful hygiene, and later on we shall see what will be the best way to effect this; but let us at once urge here that the necessity of having the bowels moved daily should be insisted on from earliest childhood. Especially is this of the greatest importance in the case of young girls, for with them this most necessary rule of hygiene is so often neglected. There is no doubt that, in many persons, fæcal matter can stagnate in the intestines for a few days without much consequence, as the epithelium of the intestines, when in sound condition, may prevent the entrance of poisonous products. But it may be different when this becomes a habit; and when the epithelium is not in perfect order,—as is often the case after prolonged constipation, or with catarrhs of any kind, or with excreta which by their shape may injure the epithelium mechanically,—resorption will follow. At any rate, it is an every day occurrence for persons who have not had their bowels moved, even for one day, to complain of headache and other symptoms of uneasiness, so that it is impossible to regard these as simple reflex actions, as some are disposed to think, but rather as symptoms of auto-intoxication. Therefore the necessity of clearing the bowels every day should be insisted on, and again especially in the case of the young girls, for it can easily become a bad habit once they have begun to neglect it, and the sluggishness of the bowels, to which females have a peculiar tendency, is thus further encouraged. Everything should be done to prevent habitual constipation in young girls, for the important reason that stagnation of blood in the adjacent organs of the pelvis is otherwise promoted, and thereby also a tendency to subsequent diseases of the sexual organs, from which many women suffer, at any rate much more frequently than men. This movement of the bowels every day can best be secured by appropriate food, such as exercises a gently stimulating action on the walls of the bowels. Drugs should be avoided as much as possible, for reasons we will mention in another chapter. Habitual constipation, if persisting for years, can certainly facilitate the oncoming of old age, while its appearance can be considerably deferred by a good movement every day, owing to the prompt release from the organism of a mass of toxic products.