D.S.I.R. Shows How It Serves Public

Press, Volume CV, Issue 31009, 15 March 1966, Page 18

D.S.I.R. Shows How It Serves Public

A bird’s wing found in a pound of butter, a machine for separating cupro-nickel and silver alloy ‘half-crowns, a scrap of cardboard torn from a matchbox which led to an incendiarist’s arrest—these articles have something in common. Included in a display organised by the chemistry division of the Christchurch branch of the Department of Scientific and Industrial Research, they illustrate ways in which a scientific laboratory serves the community. Each section of the display, containing charts, illustrations, samples, and working apparatus, represents one of the division’s activities.

“Whatever you eat, we test" reads a poster in the food and drugs section. This covers the search for contaminating and adulterating materials in food; tests for fat content and pasteurisation of milk; determining the strength of alcoholic drinks; and inspection of bacteria in food, containers, and water. A noteworthy feature is a chart indicating how the 56 tons of stones discarded each vear by apricot processors could yield useful bv-products such as ground kernels, kernel oil, and marzipan substitute. Separating Coins The machine for separating half-crowns was invented by the division’s physical chemistry staff at the request of the Reserve Bank and the Decimal Currency Board. Something had to be done with 15m half-crowns being withdrawn from circulation: there was a demand for silver alloy and a demand for cupronickel. but not for a mixture of both. The division was asked for a machine which could sort eight coins a second, with a margin of error of one in a thousand. It developed one

which sorts 15 a second, and, except with mutilated coins, is 100 per cent accurate. Forensic Science Visitors were especially interested in the forensic science section, where they learnt how experts recovered inflammable liquids used to start fires, revealed serial numbers filed off car engines, or detected alterations to cheques and documents. Crime is also the theme of an exhibition of equipment for opium smoking, samples of narcotics, and devices used —apparently unsuccessfully—for smuggling drugs through the customs. Other parts of the display are devoted to chlorination and fluoridation of water; the testing of town gas supplies; the nature, sources, and control of air pollution in Christchurch; alcohol and driving; and uses of ultra-violet light. Selected aspects of the chemistry division’s work are presented in a programme of coloured slides, and there is a review of the development of the division from its establishment in 1865 until its centenary. Even the most complex exhibits, such as the gas chromatograph and the spectrophotometer, are set up and documented so that they can be approached readily by both the general public and those with specialised knowledge.