Scientific and Useful

New Zealand Graphic, Volume XL, Issue 1, 4 January 1908, Page 38

Scientific and Useful

BOLAR SYSTEMS IN MINIATURE. The word “ atom ” for cent uries was taken to mean something indivisible; but in these scientific days it has belied its name. The atom of hydrogen, the smallest and lightest of them all, is now •believed by the most eminent scientists to be made up of about seven hundred “ electrons,” a name given to the ultimate particles of matter, each of which is charged with electricity. Sir Oliver Lodge has ventured the suggestion—a bewildering one—that we consider an atom of any element as an infinitely little solar system. if the electron be conceived of having the size of the period at the end of this sentence, then the size of an atom of hydrogen will be that of a church building one hundred and sixty-eight feet long, eighty feet wide and forty feet high. According to the chemists, less than a thousand electrons occupy the atom, in a sense that an army occupies the-coun-try. They prevent the entrance of anything else; they make the atom impenetrable, althougli they do not fill a trillionth part of the space with their actual substance. The electrons are in violent motion among themselves, having a speed probably one-tenth that of light—thousands of miles a second. Yet there is little danger of collision, for the electrons are much farther apart in proportion to their size than are the planets of our system. Thus, according to this theory, men come to an atomic astronomy, and the amazing thought is suggested that there is no such thing as absolute size, and that even solar and star systems may be atoms of a larger universe. This would seem to hearken back to the ideas of the old Greek philosophers with reference to the " atomic theory.” ♦ + ♦ MAN UFAUT U RED DI AMON DS. From paste to diamond dust, there are more things from which the imitation gems of an accommodating commerce can be easily produced than are dreamt of in some innocent purchasers’ philosophy; but, hitherto, the expert with chemical knowledge and an eye has always been able to distinguish a real earth-born stone from a manufactured one. According to the Paris correspondent of the “ Daily Telegraph,” chemistry promises at last to defeat his nicest scrutiny. M. Aristide Charette has presented to the Academy of Science a veritable diamond that purports to have been made from ordinary black carbon by a simple process. To be technical, you cause a feeble current of electricity to pass for several days through a liquid sulphate of that element mixed with iron; and thereupon the carbon crystallises out. M. Moissan’s recent discovery that, he could produce minute crystals by tremendous heat and sudden cooling under intense pressure is thrown »ato the shade, for the crystals obtained by M. Charette are much larger and cheaper. However, there is no immediate and unmistakable. warrant for panic, either among ladies who have tiaras, and necklaces, or in Hatton Garden, or on the South African sharemarket. Even in precious stones of one description, there ere qualities and qualities. M. Char rette’s nne specimen has yet to be judged for colour and brilliancy. THE GOOSE TRAFFIC OF BERLIN. The traffic in geese at Berlin amounts to nearly £400.000 a year. As the domesti' supply is wholly inadequate, a special goo.-e train of from fifteen to forty cars arrives daily from the Russian frontier. Each car is specially built, and carries about twelve hundred geese. There is a rigid inspection by sanitary officials immediately upon the arrival of the train. Should it be found that a single goose has died or been ill of a contagious disease in transit, the entire cartload is quarantined for eight days. If during this period of quarantine another goose

should die, the quarantine is extended for eight days, at a cost of about £ 100 to the owners. The penalty attaching to the bringing in of diseased geese makes the owners extremely careful to import only sound and healthy fowl. The geese which are plump and ready for market are sold to dealers at the close of the inspection. The rest, comprising the great majority, go to feeding farms in the suburbs of the city to be fattened for market. Tiiere is a special market near the great market place at which bracken—namely, geese injured en route, but having no disease—are sold at reduced price. Twenty-one different varieties of the Russian goose are commercially recognised, and the wholesale price varies from 1/8 to 2/6 a bird. EXPLOSION BY MUSIC. One of the most dangerous of all explosives is a blaek powder called iodide of nitrogen. When it is dry the slightest touch will often cause it to explode with great violence. There appears to be a certain rate of vibration which this compound cannot resist. In experiments to determine the cause of its extreme explosiveness, some damp iodide of nitrogen was rubbed on the strings of a bass viol. It is known that the strings of such an instrument will vibrate when those of a similar instrument, having an equal tension, are played upon. In this case, after the explosive had become thoroughly dry upon the strings, another bass viol was brought near and the strings sounded. At a certain note the iodide of nitrogen on the prepared instrument exploded. It was found that the explosion occurred only when a rate, of vibration of sixty a second was communicated to the prepared strings. Vibration of the G string caused an explosion, while -tnat of the E string had no effect. ♦ ♦ ♦ PLANT CULTURE UNDER THH ELECTRIC LIGHT. Some years ago the late Sir W. Siemens, by his experiments, demonstrated the possibilities of assisting plant-culture by means of the electric light, investigations which have since been followed up in the United States. In this country, however, no further researches have been undertaken until recently, when Mr. B. H. Thwaite once more resumed operations. His system is now being practically tested at the Royal Botanic Gardens in Regent’s Park, London, but upon more advanced lines than has yet been attempted. The electric light is so arranged that it traverses the whole of the greenhouse in which it is installed, and returns. The light, before reaching the plants, passes through a glass trough of water so coloured as to resemble the density and character of our atmosphere through which the sun’s rays have had to penetrate, so that the conditions are made as similar as possible. The current is generated from a dynamo driven by a gas-engine of special design, and this not only furnishes the requisite energy for the actinic light, but also the heat and chemical gases necessary to stimulate growth. The experiment is one of great interest to those concerned in the problem of intensifying plant-growth under glass, especially in view of the fact that the Thwaite system is based upon novel lines, since in addition to the light, the economic use of the waste gases and heat generated in the water-cooling circulation for the engine dispenses with the necessity of the usual heating arrangements. The inventor claims that the whole cost of his apparatus and its operation represents ‘an expenditure of only one penny, as compared with threepence per hour for the general system of assisting propagation by heat. The progress of the plants under the influence of his culture at the .potanical Gardens will be closely followed by horticulturists during the next few months, especially in those periods of dull, foggy weather when plant-growth ia almost reduced to stagnation.