SCIENCE SIFTINGS

New Zealand Tablet, 1 December 1921, Page 46

SCIENCE SIFTINGS

===== By "VOLT" =====

THE HYGIENE OP SLEEP. { The majority of people in this country do not have sufficient sleep (says a British contemporary).Eight hours of sound' sleep is enough for the average adult in good health. This does not mean simply eight hours in bed, but that amount of solid sleep night after night. To be sure there are persons who apparently do well on six or seven hours of sleep in the twenty-four, but these are rare exceptions to the rule. Many persons in good health cannot be at their best without nine hours of sleep every night. Yet very few in active life get as much as six or seven hours. If this amount is required for one in health who is not exhausting more nervous and muscular force each day than his organic capacity can restore, then it is rational to conclude that when there is unusual strain of emotion, intellect or muscle, more rest and sleep are needed to maintain the economy against wear and tear. It seems to be an accepted fact by physiologists that ultimate nutrition —that is the actual conversion of the blood elements maintained by food into the various structures of the body as nerve cells, muscle fibre, bones, etc. — takes place mainly while these structures are in a quiescent state, or, so to speak, "off duty." Hence, unconsciousness represents the best condition for nutrition; and normal unconsciousness is sleep. It is, therefore, when the brain and whole cerebro-spinal nervous system are in repose that exhausted force and the power to direct its expression can best be renewed. While then it is true that simply resting will often enable one to recover from fatigue, still the more profound rest secured by sleep is needed, especially in order that the brain and spinal nervous system may be rehabilitated each twenty-four hours to such a degree that health and strength are maintained and not slowly wasted away. There are some false notions afloat regarding sleep, and persons are sometimes considered lazy and shiftless if inclined to sleep more than is the custom. The truth is y the faster the pace —and in these days it is becoming so hurried that many good people are compelled to withdraw from the —the greater the need for long hours of recuperation. Our forefathers did not need as long hours of sleep as do their dependents. They tired more slowly. Then there were no railroads, bicycles, automobiles, no telegraphs, telephones, stenographers, and typewriters, no Stock Exchange excitements, no vast monopolies against which the individual must too often throw away his life in competition. All was comparatively serene and placid, and men had time to live serenely without perpetual nervous strain. " It must be borne in mind that to-spend more nervous energy each day than can be evolved from rest and food is to become sooner or later physically bankrupt. There is but little danger that any one in active life will sleep too much. To you who are exhausted, worn out, sick, the plea is made that you set to yourselves the task of adding faithfully one or two hours more to your sleep each night, and in this way gain enough in nervous power and control to enable you to live without stimulation of one kind and another. j. One often hears it said by people who like to sit up late at night and lie in bed late in the morning that the morning nap is particularly refreshing. This may seem so, but it is a fact that for purposes of best recuperation the old adage of "ah hour before midnight is worth two after it," points unerringly to the better way, and for this reason: rest comes from an upbuilding of the nerve centres and muscular structures, and a general reconstruction of the tissues, including the fluids of the body. This ultimate nutrition or exchange between the tissues of the body, the blood and excretory fluids takes place more rapidly and thoroughly before midnight, because then there is a more rapid and thorough circulation of the blood carrying new material to and removing waste matters from the tissues.