SCIENCE SIFTINGS

New Zealand Tablet, 13 February 1919, Page 46

SCIENCE SIFTINGS

By "Volt."

Merits of Aluminium. Dr. W. Rosenhain, in a London address on "Aluminium and its Alloys, said that aluminium alloy was not a German monopoly. A Zeppelin framework had a tensile strength of 25 tons to the square inch, but this was not so good as the combination of lightness with high strength that could be produced in Great Britain. Comparing steel having a tensile strength of 28 tons to the square inch with pure aluminium of 7 tons strength to the square inch, he said that the length of a vertical bar of steel that could just carry its own weight would be 19,000 feet, and of aluminium 14,000 feet. But with alloy the length of the aluminium bar would be extended to 50,000 feet. In large structures like bridges the weight of the structure was so great that the weight of a train was almost negligible, but the point came where the span could only just carry itself, and, in comparison with steel, the light alloys of aluminium could increase the limiting span threefold. There was great expenditure of energy in starting and stopping electric trains, and if the heavy steel parts of locomotives could be replaced by light alloys there would be quicker starting and stopping, and an important saving. There was a prejudice against aluminium, and the permanence and stability of the alloys had been questioned, but research had cleared away doubts. The main consideration that interfered with the use of aluminium was that of cost. Aluminium was extraordinarily plentiful in the earth's crust, and we needed a method of extracting it cheaply. Cheap electricity was essential, and he looked for this to the full utilisation of our water supply. The Medicinal Value of the Eucalyptus. An Australian lady (Mrs. Lance Rawson) writes thus about the eucalyptus: "Living away in the bush, many miles from a medical man, arid with a young family subject to the usual ills that child life is liable to, I found eucalyptus leaves a sort of universal remedy. I have used them even as a poultice for wounds and gatherings, and for sore throats the steam from an infusion of young leaves always gave relief. I believe if a bath in the water in which the leaves have been soaked was given in cases of low and colonial fever a cure would be effected much sooner than is usual with the ordinary remedies used. The after effects of a bath as I describe are delightful, but the leaves must be used. I have tried the extract in the water, but not with the same success. For a child feverish through teething or any other infantile disorder nothing is better than a hot bath in which young gum leaves have been soaked or boiled. The best way is to fill bags of mosquito net with the tender : shoots and leaves and pour the boiling water over them. I have tried this over and over again with my own children, and never found it fail." A volunteer worker who has been attending influenza patients in the country says that a simple precaution he suggested had been attended with wonderful results. Every infected home he visited he advised the occupants to boil bluegum leaves and let the steam permeate every room. This not only acted as a tonic, but as a disinfectant.