MODERN SCIENCE.

New Zealand Herald, Volume LXI, Issue 18885, 6 December 1924, Page 7 (Supplement)

MODERN SCIENCE.

TEMS OF INTEREST.

A' RIVAL TO SILK.

COTTON AND CHEMISTRY.

Cotton is gaining upon its rivals by aid of the chemist. Silk, the aristocrat of textiles, gets the gloss that is the envy of the rival fibres from being lorced out In a viscous form from the. tiny orifices of the spinnerets of the silkworm, solidifying as a single, slick, smooth cylinder a thousand vards long- Cotton, on the conIrarv if "compared under a microscope, looks'like a short twisted tape, and wool like a rough ami scaly ropj. Cotton, to n'uotc an old joke, shrinks from soaping Z-liko a small boy. Dinning cotton into strong alkali causes the fibres to shorten and Thicken and soften. _ Seventy-five years ago it occurred to an English chemist, John Mercer, to see what would happen if the cotton were not allowed to shrink. So he kept the thread or cloth on stretchers while it was dipped jnto a solution of caustic soda and left to drv under tension. This lye took the kinks out of the cotton and softened its surface. and this gave it something of the lustre of silk So Mercer immortalised hansel:, like J ' L. MacAdam, the road-maker, and wo have had "mercerised" cotton ever 6ince. Now a new method of treating cotton has been invented. This is the opposite 0 : the mcrcerisation process for it is produced by acid instead of alkali. Charles ft-bwartz, of the Philana Company, at Tasle, Switzerland, has found that cotton may be made to resemble its own rival, ■wool, by immersing it in concentrated nitric acid. The fibres become more curly fend their surface rougher, and the fabric assumes tho texture of a new material to fight and touch. The tensile strength is t-aid to be increased by 50 per cent., and the resistance of the surface against scraping to be improved by 200 per cent. In wear and warmth and appearance the pbilanised cloth resembles woollen. The chemist has made a new market for cotton waste by dissolving it completely in nitric acid, alkaline sulphide, or acetic acid, and spinning out the viscous fluid'into threads of any length, size, and j-hape he pleases, producing thereby a fynthetic fibre that closely resembles silk in appearance if not in strength. Fifty ner cent, of what seems to be silk nowadays comes from the chemical laboratory instead of from tho cocoon. A TREE THAT WHISTLES. A whistling tree has just been brought to Paris, and efforts are to be made to acclimatise it to the Paris air. It grows principally' in Barbados and parts of the Sudan. Tho leaves have small holes in them, and when a gentle breeze passes through them a sweet whistle results. A strong wind will cause a note as loud as a siren. FINLAND HYDEO-ELEOTEIO PLANT. Finland's largest hydro-electric power utation, harnessing the energy of the Vuoksen Rapids, is well under way. The total head is to be utilised in four steps, the second being now under construction. When the plan is fully realised there will be a yield of 392,000 turbine horse-power, with 'a possibility of increasing this to 680,000 horse-power through controlling i the water level of the Salma lakes. f LIFEBUOYS WITH LIGHTS. Lifebuoys are to be equipped with selfIgniting water lights, so that in the case of an accident at night the victim can see the lifebuoy, and swim to it.' A copper cylinder is inserted in . the lifebuoy containing calcium carbide and calcium phosphide. When the calcium phosphide becomes wet, a small flamo is produced which > ignites the {; stream of acetylene. S The light burns with an intensity of 150 candles for 45 minutes. * GASOLINE FROM GOAL. 'According to experiments that tfiava been made in Mannheim, Germany, the Germans hs.vo succeeded in making gasoline from coal. A report from the American Consular Service indicates 'that_ a plant has been established for making about 60 tons of gasolino a day from coal, whereby its chemical nature is changed. About 90 per cent, of tho coal is thus converted into a liquid which is similar to fuel oil in its chemistry and fuel value, I ARTIFICIAL EGG SUBSTANCE. A substitute for white of egg and yellow of egg is made from fish roe, according to a patent German process. The roe is first extracted with fat and lecithin solvents, such as alcohol and ether, and then, after the solvents have been removed by evaporation, the substances remaining are treated with a hvdrating agent cntil they take on the oaour of egg yellow. This mass is then mixed with protein substances or tho protein residues obtained in the extraction of the fish roe. Palladium, precipitated on very finely pulverised infusoria] earth, is umid as a catalyst in tho hydration. About 40 parts egg substitute can bo obtained from J.OO parts of codfish roe. J POISON GAS AND ANTHRAX. Should skins suspected of harbouring anthrax spores be disinfected with poison gas? This question was raised at the meeting of tho committee of experts from tho League of Nations and the Interrational Labour Office, held at Geneva recently to inquire into processes of disinfecting such hides and skins. It was suggested that skins may be disinfected by gas in tho holds of the ships in which they arrive. One gas was ruled out because it destroyed the metallic parts of ■ ships, whila another was excluded because if. sometimes failed to kill rats on board, arid, therefore, could hardly bo relied upon to kill anthrax spores'. The committee decided that tho question should be studied in detail by its members in their respective countries. SEEING THROUGH A BRICK WALL. If there was one -thing which used to be thought, impossible it was seeing through a brick wall. But that idea will have to bo dropped now, for Dr. W. D. Coolidce, who invented the most powerful ana penetrating kind of X-ray tube that is known, capable of photographing the human body through and through, fmd of detecting flaws in steel forgings and iron castings, has just shown a new portable X-ray apparatus which will photograph through the wall of a house <>r the floor of a room. The whole apparatus weighs only 301b. is easy to carry and handle, and can be worked by linking it up with the ordinary electric light switch of a household. Ko plumber need be without it, and the builder, the plasterer, and the electrician Till find it useful. I SCIENCE OF MODEL YACHTS. It is not widely realised that, model yachting is a science, having a definite bearing on the knowledge of navigation and .seamanship generally. Models are Guilt to scale, every fitting being mathematically accurate, and the size of tho Mils is worked out with great exactness. valuable facts about the vagaries of winds »nd currents arc revealed by this means <Jne of the best-known enthusiasts, ViceAdmiral 0. F. Gillett, tells how, when in the iNew Hebrides, he wished to comtunicate with tho French garrison. " All our ship's boats were in use, so I fastened, a letter to the masthead of one of ny model _ boats with instructions how to set the sails for the return journey, and lent the vessel out. In due course it came I Kick to the ship's side with the answer." *u' S i is only one of many instances in wnieh toy yachts have proved their worth. Model yachts, built on the line? of the vessels competing for the America Cup, nave played by no means an unimportant Part in the annals of that famous, race, as » others.