MODERN SCIENCE.

New Zealand Herald, Volume LX, Issue 18571, 1 December 1923, Page 4 (Supplement)

MODERN SCIENCE.

ITEMS OF INTEREST.

GERM-KILLING GLAURAMINE.

CHEMISTS- DISCOVERY.

A remarkable »t f ory, orginating in experiments on the Western Front, > lies behind the discovery of glauramine, the powerful germ-killer which attracted the attention of hundreds of doctors at the London Medical Exhibition in Westminister. The new antiseptic is one of the fruits of five years' research : work carried out by two young Lanchashire chemists, Dr Arnold Renshaw and Mr. Thomas H. Fairbrother, both of .Manchester.; :■ The two youfg workers, realising that there was - scope for the application of dyestuffs to the whole field of antiseptics, examined exhaustively the'- entire range of such dyes as could be applied to the work, and* their results have shown them which groups, of dyes possess good antiseptic qualities and which do not. They made an almost dramatic discovery, for example, in regard to the yellow dye auramine. First, they tested it upon a Manchester victim of filariasis, an incurable tropical disease in which tiny worms multiply i:i the blood and grow bigger and bigger until death supervenes, taking a drop of the man's blood, they tested it under the microscope with one drop

of the yellow, dye diluted four thousand times. In five minutes till the little wriggling worms were dead. Other microbes succumbed. in fifteen minutes under one drop of auramine diluted twenty thousand or even forty thousand times; and it is froiiV auraminb that they have obtained the new antiseptic, glautamine. The high state of dilution in which the preparation is being used for nose and ear surgery, for cleaning the skin prior, to operations, and other 'allows the stain left by the germ-killer, to he ; readily removed. Its two .-discoverers are now bis v pursuing their investigations . into the 'properties of other dyestuffs.

ELECTRIC DBIVEN VESSEL. . A most important' development- in marine engineering is represented by the first J)ie*el electric-driven vessel—La Plaza, built by Cammed, Laird's at Birkenhead to the order of the United Fruit Company, America— took the water m the Mersey Channel a. few weeks ago. She has a cargo capacity for 7,000,000 bananas. Technical experts representing all phases of marine engineering and shipbuilding accompanied her arid were delighted with her performance. : Mr. W. L. Hichens, chairman of Camrocll, Laird's, speaking at a luncheon during the trip, said that any. future difficulties would be of detail and not of principle. r l :■. » ' '

SAFETY IK STEAM BOILERS. Throughout tho world, red is . ini stinctively recognised as the warning signal and under no circumstances is it more desirable to show the red light of danger than tvheii the water runs low in a steam boiler. Generally, a ; red line is marked on a scale behind the gauge glass to indicate the lowest level compatible with safety, but it is then riecessarv >o hunt for the actual level of the water in the tube. The red index line is easily seen but the meniscus or surface laver of the water is not easy to locate in a'badly lighted boiler house or if the gauge glass bo somewhat dirty. An ingenious means of making the meniscus itself ? stand out as an unmistakable red line has been devised by a British engineer. A ventilated metal tube containing a small ;• electric i lamp is ,itta/?hed to the gauge glass and the rays from the lamp pass through an optical class transmitter, coloured red on to a reflector by which thuv are directed on to the meniscus. The lamp can be supplied from a battery or other source of current, and it can be alight continuously or connected to a switch-button which the attendant presses whenever he wishes to note the water level. So long as the lamp is alight the meniscus shows up as a liminous red line, the position and import of which it is impossible to mistake. SHIPS WITH GLASS BOTTOMS. An invention has been brought out by a British pilot which will have the effect of lessening the risk of a vessel running aground in shallow water or in- fog. In the bottom of the ship is a small window of very (thick glass, through which a searchlight throws a strong beam of light on to the bed of the ocean. Above the window is st pate valve which, if the glass should get broken, could »be- closed instantly to prevent flooding. , ! Toward the bow of the ship is a, gunmetal .chamber open to the sea at the bottom, containing a tube which can bo moved from the inside.' This -tube is 'directed on to the point of light cast by the searchlight on the bed, of the sea, and the angle it haii,- to make to hit this spot is recorded. -^'f '/.'.':'•'..'; v./' - ••£?.•■. Given the exact distance along the ship's keel between ■ the searchlight "window and this tube, plus the angle which the tube has to make with the ship (the searchlight shines at a ; right angle) a simple calculation will work out ,- the length of the searchlight's beam. And so the captain -knows the precise depth of water in which he is - sailing. ■ When perfected, this new depth finder will eliminate the difficulties of sounding, and will tell the captain his depth in apy condition $£ westh_er.