WHEN ONIONS ARE APPLES.

King Country Chronicle, Volume VIII, Issue 696, 19 August 1914, Page 3

WHEN ONIONS ARE APPLES.

SOME ILLUSIONS—AND SOME FACTS. "Never"!" you reply instant—and nobody will pick a fault with you. For ho one would for a moment imagine anyone . mistaking an onion for an apple. But don't be too sure ! Some day, when you have nothing else to do, cut a small syuare onion and a square of apple of the same close your eyes, and hold your nose tightly, and then get someone, to hand you one of inQ squares, with-, but telling you which one it is. You would; be well advised not to wager any money on beinj able to tell by chewing which it is ! The explanation is that a large .part of what we call taste is really smell. t Altogether therb are some very peculiar illusions. which we experience every day, and yet do not notice. For instance, get someone to trace a line across 5 your wrist — which you keep; perfectly still". You will then feel as if it is your wrist that is moving—and hot. the- pcn:ilpoint ! Or touch your forehead with the fore-finger. Keep the latter, motionless, and slowly rotate your head, and you will have an irresistible sensation that it is the fingertip that is moving, and not the head. , Next, take our power of vision. There are innumerable little illusions to ' which we are all susceptible. Hold up this paper at arm's length, look intently at it, and if you notice-, closely you will find that it appears to move to meet your eye. FIXING THE EYE.

Or look round for two objects that are almost; in line with your eyeonly the one nearer to you than the other. Fix your eye on the object further ofi for a, little time, and lo ! if you just note it, the nearer object is doubled ! ; It .is one of the most interesting! facts "in psychology that objects nearer, or further off than the one our attention is fooussed on appear double to our sight. But we have habitually, unconsciously, trained ourselves not to,notice .this blurredness, and it is only v by a sharp and constant use of our wits that we can now observe it. . There are some interesting facts, too, in connection with the brain. How many people know, for instance, that it is the right-hand side—or hemisphere of the brain—that manages, or works, the left-hand side of the body, and vice versa ? " Most people know —or have heard, at any rate —that the brain is one of the most complex little machines in the universe. The outer core of. it, of greyish matter, is called the cortex. And a wonderful thing it is ! It is made up of little cells,' each connected by hundreds of fibres —and there are 3,000,000,000 of these cells! So that our system is infinitely .more delicate and complex than we generally suppose. BARS AND HEARING.

Even in, sayj the inner ear, besides ccmntlessi other minute organisms, there is a> little tunnel —for protecting dslicate fibres —that is composed of over ten thousand reds leaned against one another, 20,000 in all for each man's hearing "machine !" Not only is the ear for haaring, but it has been found to have another function—that of warning us when we are about to fall, or of giving us the sensation of giddiness. Hence the reason why many who are deaf and dumb, and have their inner ears destroyed, are incapable of being made dizzy. Lastly, there is—what we might sail a n illusion—colour-blindness. This ma 3* take various forms. Some of you may have it in one form or another, and "yet actually not be aware of it, so little do we thin 1 * of those common everyday experiences ! For instance, one fairly common kind of colour-blindness is that of seeing red as green, and vice versa. It is perhaps not Known that many people are afflicted with this defect. Normally, of course, it doss not matter very much ; but one can easily imagine how dangerous it might be in the case, say, of a signalman, or an engine-driver on the railwayIt might be worth our wliiilc, after all, to test the matter with your friends. —"Answers."