Dancing combines wholesome exercise, social enjoyment, and the acquirement of skill and grace, but it is seldom of much hygienic value because it is frequently overdone, and often involves bad air and loss of sleep. In one large plant where the employes were examined by the Life Extension Institute, the management regarded the harmful effect of dancing as their chief obstacle to efficiency. Many of the large force of girls and women were accustomed to dance until late in the night, bringing on a condition of chronic fatigue. [Sidenote: Card-playing] Card-playing and similar games afford wholesome mental recreation for some persons. However, they, too, are liable to be associated with late hours, and other disadvantages even when they do not degenerate into gambling. Card-playing, dancing, and many other popular forms of amusement often border on dissipation. [Sidenote: Suicidal Amusement] Amusements which weaken and degrade are not hygienic. Many who need amusement make the fatal mistake of getting it in suicidal ways, in the saloons, dives, and the low dance-halls. Play is simply a half way stage between work and rest. In a hygienic life there must be a certain amount of actual rest. Every bodily power requires rest after exertion. The heart rests between beats. The muscles require relaxation after every contraction. The man who is always tense in muscle and nerve is wearing himself out. [Sidenote: Relaxation] The power to relax, when fatigue requires it, is one of the most important safeguards one can possess. Lying down when tired is a good rule. A very hard-working college president when asked about the secret of his working-power and length of life replied, "My secret is that I never ran when I could walk, never walked when I could stand, never stood when I could sit, and never sat when I could lie down." [Sidenote: A Rule for the Lazy] Such rules as these are valuable, of course, only when the requirements of one's occupation tend toward ceaseless activity. For idle and lazy people the rule should be reversed--never to lie down when one could sit, never to sit when one could stand, never to stand when one could walk, and never to walk when one could run! A complete life must have all in due proportion. Relaxation is only a short vacation, as it were, between two activities. [Sidenote: Bathing and Swimming] Bathing and swimming supply, in their numerous forms, examples of both healthful activity and relaxation. A cold spray or shower, alternated with hot, affords excellent gymnastics for the skin. A very hot bath, lasting only a minute, or even a hot foot-bath, is restful in cases of general fatigue. The most restful of all is a neutral, that is, tepid, bath of about the body-heat (beginning at 97 or 98 degrees and not allowed to drop more than 5 degrees and continued as long as convenient). [Sidenote: How to Induce Sleep]