Mental, physical, sensory and emotional activities, in fact, anything requiring action, use up nerve energy, but when indulged within normal resistance, rest and sleep, restore expenditure. When we persist in spending more nerve energy than rest restores, we become enervated. Activities carried beyond nature's power to compensate during the hours usually allotted to sleep and rest and relaxation wear out the nervous system.

The several capacities of the various organs of the body are not defined to a minute fraction, for nature has made such grand provisions for the safety of the organism as allow and endure considerable latitude.

A normal man or woman is one whose digestion, secretions and excretions are balanced; one who eats within his bodily needs, whose secretions are normal in quality and quantity for carrying on the work of the body, and whose elimination removes from the body all the waste products. Such a body possesses a wide range between the minimum and maximum of these and other functions, before encroaching on the laws set by nature which declare "Thus far shalt thou go and no further, without paying the penalty."

Within wide limits nature has provided ample freedom for ignorance and indulgence. But the body is not absolutely fool-proof and "human stupidity and incorrigibility exceed even the wisest calculations of the gods." The average limits of the functional powers cannot be habitually and persistently overstepped without resulting in a corresponding weakening not alone of the overused function, but of the whole body.

What the average person calls rest is no more than a change from one form of enervating activity to another. The unpoised who never relax, but hurry and joy-ride through life run into indigestion, toxemia, hard arteries, premature senility and an early terrestrial exit. Only those who learn to relax completely, physically and mentally, really rest.

Dr. Weger says: "Speed mania has the modern person. From morning until evening, and again until the early hours of the rooming, it is one mad rush, overanxious and overeager to outdo their friends and their foes, until they at last lose entirely, not only the balance of their minds, but the absolute control of their bodies. Thousands perish from year to year in the mad rush--the feverish and impatient and unnecessary excitement of love, of pleasure, of business, and of the social whirl."

"These" he says, "are the ones who are wrecks at forty, and in their graves at fifty; for they overtax their strength by assuming fearful responsibilities, and by taking long chances, filled with direful fears and dreadful anxieties. Many of them fancy that they must be here, there or everywhere; for, by an exaggeration of their self-importance, they imagine that the world's work cannot get along without them."

In a broad sense, loss of sleep, "tired nature's sweet restorer," almost her only restorer, typifies all other enervating influences. During sleep conscious activities--mental, emotional, sensory, physical--are suspended and the production of metabolic waste is reduced to a minimum. Usually the sleeping person is taking in no poisons from the outside.

During sleep the body is busy appropriating nourishment and eliminating waste matter, recharging her nervous batteries and storing up energy for the morrow. Habitually losing sleep is indeed "burning the candle at both ends." "After sleep the mind is quickened, and the elusive thoughts that refused audience to the tired mind, come flocking in droves to do the bidding of the refreshed mind."

Sleepiness is as natural as hunger; indeed it is a form of hunger--a craving for rest by tired nerves. Insomnia means overworked nerves--too nervous to sleep.