WHY WE MUST SLEEP.

Temuka Leader, Issue 2427, 19 November 1892, Page 3

WHY WE MUST SLEEP.

After all, science can scarcely explain the why of anything. It merely points out the order in which natural processes occur. Preyer holds that sleep is caused by the products of decomposition, lactic acid, and creatin taking up the oxygen in the blood. The functions of the grey matter of the cortex cannot be exorcised without a plenteous supply of arterial blood any more than the zinc and copper of a voltaic pile will evolve electricity without the sulphuric acid. Thus the blood conveys a stimulas or imparts a capacity to the nerve tissues during waking, while during sleep it has a separative and distinct function, that of repairing waste. Apparently these two processes cannot go on in the brain at once, or at least only to a degree too limited to prevent a speedy exhaustion of the vital powers if sleep be withheld. There is a striking disparity in the time required for sleep by different persons. Some men, like the Emperor Akbar, St. Francis Xavier, and General Eliot, the defender of Gibraltar, could do with as little as four hours’ sleep, while other men need ten hours, or even half the twenty-four. But all must sleep. A cruel form of capital punishment in China consists in artificiaetly keeping the culprit awake till he dies from exhaustion. —British Medical Journal.