SCIENCE SIFTINGS

New Zealand Tablet, Volume L, Issue 26, 5 July 1923, Page 54

SCIENCE SIFTINGS

By - VOLT

Curious Color Changes. The possibility of a man’s eyes changing their color as a result of mental shock or physical ill-treatment has been discussed by surgeons. “It is common knowledge,” stated one medical man, “that great physical hardships may suddenly turn the hair white. The loss of color follows on certain chemical changes, due to disturbances of nutrition, taking place in the tiny particles of coloring matter which gave the hair its tint.” All babies have blue eyes when they are born. In some infants pigment granules begin to develop in the iris immediately after birth. Thus they become black or brown eyed. 'ln others no such pigment formation takes place, and the eyes remain their original color throughout life. Stick and Stamp Machine. An ingenious time-saver has just been brought out by the United States Post Office. In a single operation it seals letters, stamps them, postmarks them, and counts them. The envelopes are fed at high speed on to an endless rubbed band which conveys them first under a little device - which slightly raises the flap and moistens the gum, and next to a roller which fastens the flaps down. Finally they pass through a tiny printing press, which stamps “Postage Paid ’ on each and postmarks it. I he stamping appliance is rather like a cross between a dating stamp and a cyclometer. It is set by the Post Office to print any number of stamps that have been paid for in advance, as is frequently done by commercial houses when posting circulars in large numbers. As each letter is dealt with the cyclometer ticks up one, and when the lull number is reached the machine automatically “downs tools.” It will not work again until a further payment is made. 1 hen the 1 ost Office official opens it with a. special kep and sets it once more to print as many stamps as have been paid for. Perils of the Electric Light. “Mankind is being blinded by modern electric light,” declared Mr. A. Is. Bawtree, electrochemist and physicist, in a lecture before the Royal Photographic Society (England). Mr. Bawtree seeks to bring the modern world back to candlelight, and thus restore its sight. “An appalling amount of eye trouble exists,” he added. “This vast outbreak has synchronised with the introduction of modern artificial lighting. Let us go back to the open flame and recover healthy eyesight. It wall be well worth the inconvenience. Blindness and bad sight are the worst inconveniences humanity can suffer. “Fifty per cent, of middle-class men, 20 per cent, of middle-class women, and a large number of children wear spectacles. Out of doors many of them have to use dark glasses. Glasses may be becoming, but, like crutches, they betoken disease or deformity. “There are four reasons for all this eye trouble, The first is that electric light is too intense. Mankind through all the ages till 1890 used the open flame. The open flame, however it was produced, never exceeded an intensity of two candle-power per square inch of flame. The feeblest form of electric lamp is at least .80 times, more intense. “The next cause of trouble is the dangerous and invisible ultra-violet rays. No bowls or shades absorb these rays. White walls and ceilings reflect them. In nature the rays are absorbed from the sunlight by trees and flowers, which do not reflect them. But the electrician floods our rooms and streets with this eye poison. “A third source of eye trouble is the strain imposed on the eyes when a person suddenly comes out of the darkness into a blaze of. light, or suddenly turns on a switch. “The fourth danger in electric lighting is the alternating current which is frequently used. This causes ‘ induced currents ’ in the nervous system and produces fatigue. “The ideal solution- would be to go back to candles. Man must take a bold step.”