SCIENCE NOTES.

Otago Witness, Issue 3100, 13 August 1913, Page 68

SCIENCE NOTES.

Use of Marble in Lighting.— It is reported that patents recently have been taken out in Germany for using marble instead of glass in lamps, which medium has the effect of making the illumiration scarcely distinguished from daylight. A number of experiments have been made wit’, tinted and patterned types of glass, with the idea cf producing this effect. Marble was planed down until it is difficult to realise that it is artificially lighted tensities of light were shown from behind. The result was exactly what so many hundred j of experiments had failed to produce. Developing this discovery, the inventors fitted lights to the cornice of a room so tha; it was somewhat transparent. Ozone and Pino Trees.— What is the reason that pine and fir trees and others of the species are surrounded, more than other trees, by ozone, and that therefore forests of the “ needleleaved- ’ trees are so health-giving? If die theory of Professor Lomstrom, of Helsingfors, is correct, this can now he explained; for the “ needles ’ act on the atmosphere as generators of electricity, so that the trees are always surrounded by electricity and consequently by ozone. Professor Lemstrom liegan his researches in this direction by studying the uses of the spikes or “boards” ot grain (wheat and rye), which lie found to be generators of electricity which the plant requires for its proper development. Aniline Dyes and Microbes.—

That aniline colours have a marked action upon various kinds of microbes appears to be established by the recent work of uS. Kriegler, He studies the effect of a certain number of aniline colours upon microbes such as typhus, cob. and others, and finds that aniline compounds in general act to destroy microbes, this being even in greater degree than phonic acid. Of the different bacteria ho examined ho finds that the typhus bacillus is the most readily affected. On the other hand, he remarks that not only can there exist differences in microbe-destroying power Ivetween the different aniline colours for the same microbe, which are easily explained by diversity in chemical nature, but be also notes that the same colour compound dons not possess an equally strong power upon different kinds of microbes. In fact, a given aniline colour substance may act as an antiseptic in destroving one species of germs without necessarily being active as regards another species. Cork Paper and its Uses.— Enormous quantities of cork are used annually for making tips on cigarettes. For this purpose the cork is converted into very thin sheets which constitutes what is known as cork paper. These sheets are exceedingly thin, and come in the market. 4£ir. in width and 61n, Tin, Sin, 9in, and lOin in length. A package of about 250 sheets is scarcely an inch thick. It is estimated that approximately £IOO.OOO worth of cork is converted into cork paper every year, and almost all of this is used for making tips on cigarettes. The thin pork is pasted on long sheets of paper, which are passed between rollers and automatically covered with paste, while girls with deft fingers lay on the cork and smooth it down as the paper passes along. After this the sheets are passed through the cutting machines, in which they are divided into eight strips jin wide and wound on reels for use in the automatic cigarette tippers.

Eaoh of these machines lias a capacity of 10,000 sheets of cork paper per day. - .The total number of sheets used in the world is about 100.000.000, or about a quarter billion square feet. The cigarette-tipping machines

have a capacity of about 60,000 cigarettes daily. The cost of the finished tips to the cigarette manufacturer is from 4J>d to lOd a thousand. Frozen Coal Shafts. — It was not mini 1835, when Poctsch invented the " freezing method." that Holland s coalfields became of any practical value. Iho coal is found in the province of Limburg, and, what is more, the two mines near Korkradc in that province w< re the very first, coal mines operated in continental Europe in mediseval times. When, after 1860, the mining industry came to be more seriously considered, and several concessions had boon given out by the Dutch Government, it was found that the coal layers could not properly be reached, for in every place, except in the two mediaeval mines near Kerkrade, where coal is encountered immediately under the solid rock, there is a stratum of drift sand that contains great quantities of water. This condition of things made it practically impossible to build the shafts, which had to be of considerable depth, for the ooal layers are encountered at a depth of from 30Cft to 1000 ft. The freezing method, however, has successfully solved the problem, and Holland now has a flourishing mining industry. On tlie spot where the shaft is-to be dug from 25 to 30 borings are. made down through the drift sand to the solid rock in a circle sft larger in diameter than the projected shaft. Pities are then sunk into those boreholes, and through these is circulated, by powerful freezing machines, a chemical solution cooled down to minus 20d.g (In th:> way the drift sand containing the water is frozen as hard as a rock after the freezing machines have boon working day and night for two months. In this frozen cylinder of sand a shaft is cht-a dug and lined from bottom to top with strong segments of cast iron securely soldered together with lead. Stimulating Plants bv Radium.—

Professor Hans Molisch announces that radium causes twigs of various kinds to begin “budding’’ much earlier than normally According to the Naturwissensehaftliche Rundschau, Hrrr Molisch made use bot.li of the radium emanation and of radium salts enclosed in glass tubes or spread on metal plates. The tubes held radiumbariumchloride. The metal plate gave off strong A-rays, which were almost entirely absent from the glass tube because of the absorption. In the experiments with radium emanation, the rays from a flask Idled with an aqueous solution of radium chloride passed into a cylindrical glass vessel, which was the culture-chamber. The twigs placed in this were exposed to a radium emanation ranging from 1.84- to 3.45 millicnre. Only the twigs of Syringa vulgaris were used in the former case, but various plants were exposed to the emanation. The terminal buds of the springa, which were subjected to the influence of the radium preparations for one or two days in December or at the end of November, and then placed in ordinary light in a greenhouse, budded in a short time, while those not thus treated budded much later on, or not at all. When the radiation was not continued long enough, no effect was visible; when too long continued, the effect was inhibiting, injurious, or even fatal. The time chosen for the experiment is also important. In September and October, when the state of rest is (irmly established, the radiation had no effect. In January or later, when the rest period is already past, there is either no difference observed, or else the twigs subjected to the rays seem slightly retarded. This is similar to thu effect of the ether and warm-bath treatments. The emanation had a more marked effect than the radium salts. This is because it. influenced the plants more uniformly and from all sides. Other plants favourably influenced by the emanation were Liriodendron tnlipifera, /Esenins dippocastanum, Htaphylea pinnutu. and in some degree Acer platanoidos. The process is too costly for commercial us l ', but is of scientific importance In connection with recent investigations of the effect of narcotics on the chemical composition of resting parts of plants. On growing parts radium preparations of like strength have an entirely different effect, as Molisch hopes later to demonstrate.