Science Siftings

New Zealand Tablet, 27 August 1908, Page 35

Science Siftings

BY 'VOLT

" .' What the Banana Yields. 'The banana " furnishes us with J ink, with handkerchiefs, with Wax, '"with blacking, with oil, with flour, ' with window cord, with brushes. ' The speaker, a banana planter from Jamaica, paused and smiled. 'You don't believe me, do you?' he said. _ ' Yet truly the banana tree .is a wonderful thing. The juice being lich in tannin, furnishes a good indelible ink and a good shoe polish. The stems yield a fine quality of hemp, and . from this hemp there are made lace , handkerchiefs, cords and ropes of all kinds, mats and brushes. The oil is used in gilding. Of banana flour, the flour ground from the dried fruit, there is no use speaking — you are too familiar with it.' Miles and Miles. ' Will we never drop miles for kilometres?' said a mathematician. ' Miles are very confusing. A kilometre the world over is a kilometre-, but a mile in America is 1700 yards, while in Sweden it- is 11,703 yards, and in China it is 629 yards. The Bohemians go in for a long mile. So do the Danes, the Hungarians, the Pole's, the Swiss. If you walk three miles a day among those people you have done pretty well ; you have covered about fifteen of your own miles. There are, in fact, thirty-seven kinds of miles. It would take eighteen of the shortest to equal one of the longest. The rest vary in size between those two extremes. Doesn't the world, then, need one measure, the kilo, that it may use without confusion? Consider : A train that goes 168 miles an hour in China would )>o only nine 'miles an hour in Sweden,' Manufactured Gems. Chemists have long tried to manufacture precious stones in their laboratories, but have only succeeded in producing one the ruby— on a commercially paying basis. Hydrofluoric acid has no effect on the new. sapphires. The imitation, however, has a specific gravity considerably lower than that of the real sapphiro and is softer than it. Another difference is that while the natural stone refracts different colors brilliantly from different surfaces, the imitations do this only slightly, or not at all. Sapphires and rubies are the same in their constituents except as to coloring. Cobalt gives the red color to the artificial ruby, and the experimenters have been trying to get blue stones by using chrome. But the process which produced rubies has failed to yield sapphires. The foreign manufacturers have refused to say how the new imitations are made. Animal Language. A sound or gesture made by an animal under any mental cr emotional impression and calling out a similar one' in another animal is an element of language. When the rabbit quickly beats the ground, its fellow rabbits know that there is danger somewhere, and they take action accordingly. That is rabbit language. When the hunter imitates the rabbit and thus conveys the same ideas, he is ' speaking ' the rabbit language for the time being.- Many animals use signs, which, of course, are understood through the eyes. The ants converse by touching antennae and feet. Many insects rub the elytra. This is animal language in its simplest form. It expresses but few ideas. But there are animals which are capable of modulating their • voices • Even the common rabbits, which seem to be mute; are constantly making sounds, which a little observation will soon disc^yer to be ever changing in volume, modulation, etc. Much of this method of communication changes when the animal is brought into civilisation from the wild, state. The- wild .dog, for instance barks very little when in freedom. How the household dog barks " and is able to express himself is well known. " -'