THE TRUTH ABOUT SLEEP.

Otago Daily Times, Issue 19009, 3 November 1923, Page 17

THE TRUTH ABOUT SLEEP.

Tt is often recorded (writes “A Doctor” in an English paper) of Napoleon, Wellington, Frederick tho Great, and many other famous men that they could keep well on an average of four or five hours of sleep per night. Arguing from this, it is often supposed that to bo able to do without sleep is the hallmark of superior ability. There is no greater mistake. History abounds in examples, equally illuminating, which point to the other extreme. The great Dr Johnson, for example, although he probably retired late, was seldom out of bed until the afternoon; Lord Nelson rarely slept less than ten hours; and Charles Darwin, notwithstanding the monumental work of Lis lifetime, could not work for more than three hours a day. It is a fallacy to try to measure sleep by hours, because the quality is extremely variable. And it is quality that counts. As a general rule the depth of sleep is in inverse ratio to its duration. An exceptionally heavy sleeper may find four or five hours sufficient, while a light sleeper may 'require twice as long. Sleep is a period of rest for both body and brain, and it is sweetest and most refreshing when both are equally fatigued. With a weary brain in a restless body sleep’ is usually difficult and, when it does come, disturbed and ineffectual. This also is true when the muscles are tired but the mind remains alert. During this resting stage the blood is busy removing the fatigue products which have drugged the nerve-centres and temporarily destroyed their efficiency. ’When this removal is complete sleep has served Nature’s purpose, and so comes to an end. Obviously this process varies in different individuals. Just as human beings differ in the way they eat, or or talk, or work, so they differ in tho way they sleep. The old tag about an hour of sleep before midnight being worth two alter probably owes its origin to those who are inclined to sit up too late. By going to hod before midnight they naturally sleep longer. There is no evidence to prove that “early to bed early to rise” brings any special reward in its train. If wo believe in it at all it is only because -we associate early rising with industry and late rising with laziness. On the other hand, some people (though they are a small minority) sleep too much. Natural sleep is always associated with temporary an.emia of the brain and if sleep he too prolonged the brain will bo slow to regain its normal activity.