Science Siftings

New Zealand Tablet, 25 May 1911, Page 979

Science Siftings

BY 'VOLT'

To Stimulate Vitality. When applied for a short time the X-Rays stimulate vitality. When applied for a long time they impair and even destroy it. A Dr. H. E. Schmidt soaked beans in water for six hours, subjected different portions of them to the X-Ray for different times, and then planted them. The beams that had been longest under the ray either did not come up at all, or had but a feeble growth, whereas those that had been under it for a short time only grew up hardy and produced a large crop. Dr. Schmidt suggests that the same results follow the application of X-Rays to animal life, and consequently that when X-Rays are used on sluggish ulcers, the exposures should be short, while in the case of malignant growths, which are to be destroyed, the exposures should be longer. A Remarkable Snow Storm. Mr. H. E. Wood describes in the South African Journal of Science for September the remarkable snowstorm that fell in South Africa, August 16-18, 1909. The area covered by the storm embraced the south of the Transvaal, the north-west of the Orange River Colony, and the higher parts of Natal. On the morning of August 17, the town of Johannesburg, for the first time in its history, was covered with snow to a depth of several inches. To many of its inhabitants, especially of the younger generation, the sight of snow was quite new; and the unusual event was celebrated as a general holiday. During the past sixty years there have been only three great snowstorms in the Transvaal, including this one. Bad Effect of Deforestation. That the stripping of trees from a country has a bad effect on a climate is indicated by the following account by a traveller in the interior of China: ' Kansu is the poorest of all the provinces of China, and the most inaccessible by reason of its defective communications. It is a treeless province. There has been universal destruction of timber. Even the fine avenue of willows and poplars planted by Tso Tsungt'ang between the two capitals is fast disappearing. Deforestation is profoundly affecting the climate. When rain falls it falls with such violence that it scars the face of the country, which is everywhere covered with soft clay of varying thickness, with no vegetation to bind the soil together.' Sound Waves and Rain Drops. From a series of observations made during thunder storms, W. J. Laine, of the Finnish Society of Sciences, shows in an interesting wa^ r that sound waves in the atmosphere affect the size and form of raindrops. He notices that a peal of thunder invariably causes a rainbow to take up a peculiar vibration and to widen in appearance, it* red end becoming almost invisible while the violet is greatly intensified. A little later the colors which the shock has obscured narrow down and are more brilliant than before. First the yellow reappears, and then a band of striking red. Assuming as true Pertner's. Rainbow Theory, which attributes rainbow colors to the mixture of the intensities of different light waves, caused by the diffraction' of light by the raindrops,#Mr. Laine concludes that this illusion of a vibrating rainbow is due to a rapid alteration of the diameter of the raindrops and the consequent variation of the distance between maxima and minima of the diffracted light waves. Furthermore, he holds this phenomenon to be due to the sound waves of thunder, and not to lightning, since the interval between the lightning and the thunder is often as much as twenty seconds. A New Alloy. A new alloy of aluminum, called clarus, for which many claims are made, has been patented in England. It is claimed that this alloy is at least 60 per cent, stronger than ordinary aluminum, and that its weight is one-third that of brass of an equivalent volume; that it will take a very high polish, equal to that which can be obtained with silver; that atmospheric surroundings do not cause it to tarnish; that castings are not brittle, but can bo bent cold; that it is suitable for castings of any size, and that, in all circumstances such castings have been found to be sound and fr.ee from blowholes and other defects. It is claimed that the new alloy is excellently suited for automobiles and for electric-railroad, railroad-car, and aeroplane fittings. The manufacturers state that it has been made into sheets, drawn into wire, and into tubes and rods; that they have spun it and stamped it, and that they have made hand-pole brackets for the underground electric railways of London, for railway carriage fittings, for carriage furnishings, street car fittings, and automobile and motor-bus fittings. It is asserted that it is very little more costly than pure aluminum. Inasmuch as in aluminum alloys .much spelter has been used to reduce the cost, the cost of production pf this alloy would be greater probably than that of alloys with heavy percentages of spelter, etc. The alloy clarus is made from aluminum of 98 to 99 per cent, purity.