SCIENCE NOTES.

Otago Witness, Issue 3115, 26 November 1913, Page 68

SCIENCE NOTES.

-—New Sun-spot Theory.— Professor A. Orta, of the observatory of the University of Santa Clara, announces that lie has discovered that the activity of the sun in phenomena known as sun spots is intimately related to the distance of comets. He says that during a period of 16+ years to date there have been 238 comets (their returns included) that apparently have influenced the action of the sun, having their perihelia concidentally with the minima of spot frequency. —Camphor as a Vitalising Agent.— Abroad, whore great pride—and just pride—is taken in the mileage per gallon of fuel that can be obtained, a small band of motorists recently has been experimenting with gum camphor as a “dope” for gasoline. Usually, about one ounce of cpnphor is placed in five gallons of gasoline, and it is stated by those who use the mixture that the operation of their motors is much superior with the camphor in the gasoline than without it. One motorist even goes so far as to claim _that ho has been able to increase his mileage per gallon as much as 20 per cent., though it would seem that the increase cannot be due to the use of the camphor alone. The idea is not new, of course, for Curtiss, at present of aeroplane fame, used it a number of voars ago in his racing motor cycles, and it is said he sometimse uses it now in his aeroplane engines. —Poison Ivy.— Poison ivy has long been a mystery both to scientists and laymen j why and in what manner it causes the peculiar rash and irritating inflammation have puzzled both botanists and physicians. At last (says Science Siftings) the reason has been discovered. Dr Mirande, of Paris, read to the Academy of Sciences in that city recently the result of his study of the poisonous weed. Poison ivy contains prussio acid. This is found principally in the young leaves and buds; in older leaves there is very little of it In three and adialf ounces of young leaves there is about a quarter of a grain of the acid. As with other plants In which prussic acid is found, the poisonous substance does not exist in its perfect form, but develops as soon as the leaves are bruised, a chemical action being set up through the union of an enzyme with a glucosld. —How Insects Acquire Caste.— The various castes of social insects have different appearances, but it has been supposed that they are alike on leaving the egg, and develop their peculiar characteristics artificially through differences in feeding or the action of parasites. , Seeking to

learn when the different forms of termites, or white ants, begin, Professor Cugnion, of Paris, concludes that, this theory is wrong. Among the several castes of" this insect, the soldiers are wingless and have very strong mandibles, and the workers, which build and bring food, have a distinct form, but neither reproduce. The caste known as reproducers, on the other hand, with a special development, appear to perform no part except perpetuating the species. The investigation made with a number' of species shows tnai the peculiarity of form exists in newly-hatched insects, and that, , therefore, division into castes, like that of the sexes, takes place before the larvte are born. —Nature’s Germ-proof Tins.— “Packed in germ-proof air-tight tins,” runs the advertisement of a new line of preserved food. One of the most useful inventions of modern times, indeed, is that of being able to preserve fresh foods indefinitely Like most inventions, however, it is not original. Nature was the first to invent a germ-proof package. Dozens of her precious seeds she protects from microbes, one of the best examples of her care being the banana. The skin of the banana is, in fact, not only proof against the attacks of microbes, but it protects the inner pulp from insects and from the decaying influences of the flir. For that reason the banana is one of the best fruits to eat, for the chances are practically nil of it carrying disease germs. Many nuts, too, are air-proof and germ-proof. If you crack a nut and it is bad inside, look carefully at the shell and you will find that a hole has been bored in it by an insect, causing it to rot. Nature, too, protects many of her children from germs. The cocoons of a largo number of moths and butterflies are not only germ-proof but air-proof. A still more extraordinary instance of this protection is shown when certain caterpillars crawl down the trunks of trees and are liable to all sorts of dangers. Before leaving the branch they cover themselves with a sticky substance, which not only completely protects them from microbes, but from their natural enemies, the birds, on account of its unwelcome odour. —A Unique Engineering Feat.— A most interesting engineering feat is at present being attempted in Switzerland at Fully-en-'V alais, where a hydraulic-electric installation is to be driven by the pressure of water from Lake Fully, situated over 1800 ft above the Rhone plain, where the power station will be situated. The peculiar feature of the enterprise is the great height of the supply. The attempt has never before been made to utilise a fall of 1800 ft, and in technical circles it has been hitherto regarded as impossible. But a Lausanne engineer, M. Boucher, has undertaken the work with every confidence of success. The pressure is so great that it is impossible to allow a direct flow, according to La Technique Modorne, which gives particulars of the enterprise. The water will flow to the valley by way of a conduit n-'arly three miles in length. The pipes will be from 2ft to 2ft 6in in diameter, and the thickness of the walla will bo from iin to 2in. In the lower portions of the conduit the pressure will be so great that the tubes will have to be mgdo of cold-drawn steel without any joins. The same necessity of providing machinery of unprecedented strength will be obeyed m the construction of the turbines at the power station. Of these there will bo four, each of 3000 horse-power. The speed or the water on reaching the turbine blades is calculated at not less than 175 metres per second, or nearly 400 miles an hour. The importance of this engineering experiment with regard ho the economic future of Switzerland can hardly be over-estimated, and others than engineers will be interested in the result. —Hastening Plant Growth.— The new methods of increasing plant growth by artificial means, which have recently given promising results, arc dependent, in the one case, on the light from mercury vapour lamps, and in the other on the use of radio-active matter incorporated with the soil. The Times states that interesting experiments recently carried out with mercury vapour lamps by Miss E. O. Dudgeon in Dumfries snowed that in certain oases seeds germinated , several weeks earlier with the aid of the light than when gmwn in the natural way The time for germination under the influence of the ultra-violet rays from the lamp was 11 days in the case of carrots against 26 days when grown naturally, while maize germinated in eight days instead of 57 with the aid of the mercury vapour light. Wheat, barley, and various other seeds were tested, and in all cases a hastening of germination resulted. Strawberries cultivated in the ultra-violet light gave an increased crop of 25 per cent., while roses, carnations, and geraniums showed increased foliage and flowers of good size and colour. As the cost of current for lighting the lamps is very low, Miss Dudgeon’s results should lead to the wider investigations of the effects of ultra-violet light on plant life A very minute quantity of radio-active material mixed with the soil has boon found to give remarkable results, but they appear to bo rather more selective than is the case with mercury vapour light. Mr i. 1 borne Baker, who has been carrying out systematic experiments during the summer with residues of varying degrees of radio-activity, has found that in some cases an increase in the rate of growth of 300 per cent. Is caused by the radium, while in others —5 e., with other plants—the increase is a« low as 7 per cent. The germination of radish seeds is particularly accelerated, and in general it was found that the stems of the plants grew abnormally tall; cabbages, for example, cultivated with radium grew tall and straggly, there being less green leaf and, therefore an inferior though larger plant. _ The presence in the soil of about one milligram of radium salt to 20 tons of soil produces, in the majority of cases tried, a marked effect upon, the rate of germination and the growth of the plants, and it has also boon used with success to hasten the ripening of tomatoes.