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Paint Section With the, improvement in the war situation, work carried out for the Armed Forces has decreased considerably and has been confined mainly to examinations for quality of miscellaneous Army, Navy, and Air Force and munition-making materials. The number of samples of paint submitted by Housing and other Departments has increased very considerably. Special examinations have included comparison of New Zealand linseed-oil with imported oil for " break " ; cement paints ; fire-retardant paints ; proprietary brands of enamels (general survey) ; traffic paints, distempers, and casein paints. At the request of Housing, painting tests wore made to determine on a variety of surfaces the relative covering powers of a range of paints prepared to Government specification. Members of the staff acted on the Paints and Coatings Committee of the Standards Institute and on inter-departmental committees for paint investigation. Problems which were studied on behalf of the committees included durability of ordinary house paints on timber impregnated with woodpreservatives ; primers for asbestos-cement and totara ; development of casein paints ; behaviour on exposure of exterior house paints ; and mould on paints. A weatherometer for the accelerated testing of durability of paints, bitumen, and textiles is now in service. A number of laboratory paint-mills and some mixing equipment has arrived and will shortly be put into use. As the State housing programme expands with the close of the war, it is anticipated that the work on paint problems and analyses of paint for quality and adulteration will increase very considerably. The new equipment will be of material assistance in this work. Spectrochemioal Section Much of the work of this Section consists of the examination of metals, largely for compliance with specification, but also including qualitative examination of steels, aluminium alloys, &c. A considerable amount of work has been done on cooking-utensils cast from aluminium scrap. Saucepans were tested with 05 per cent, citric acid, as specified for enamel ware. The ignited extract was examined spectrographically. If the metal contained over 0-03 per cent, of lead, undesirable amounts of lead were found, from 0-5 to 3 parts per million on the extracting solution. Antimony and cadmium were also occasionally found. Saucepans made from virgin metal of good quality were quite satisfactory. The citric-acid extract of a steel pot tinned with tin of poor quality also contained both lead and arsenic. There was an increase in the amount of work done on biological samples. Cauliflowers were examined for the cause of whip-tail disease, as well as apples, and the leaves of apple and peach trees. In connection with the determination of trace elements in the ash of a sample of milk-sugar sold as a " patent " medicine, a method was devised for the spectrochemioal estimation of traces of fluorine. The only forensic work was an examination of gold bullion. A point of interest was that indium could be detected in Waihi gold. A method was worked out for the spectrochemioal determination of strontium directly on rook samples instead of, as previously, on the calcium oxide separated from the samples. Physical Chemistry Section On account of the difficulty of obtaining industrial pH meters from overseas, the Section co-operated with the Radio Development Laboratory in the design of an instrument required for brewing and wool industries. The electric eye is used as indicator in a circuit. Work was done in conjunction with the Soil Branch of the Chemical Laboratory of the Department of Agriculture on the development of a conductivity method for determining the reactivity of ground limestones. The determination of resistance proved to be a simple and rapid method of indicating the content of salt in cloth for a military purpose, in which its presence caused corrosion. A number of Weston cadmium cells were made for the Radio Development Laboratory. Analyses were made of a number of electroplating solutions, and the thicknesses of various types of coating determined. The blackening of cadmium plating was ascribed to storage with traces of plating solution on the metal. Advice was also given on the surface coloration of metals, and on photo-engraving. Photographic Section A technician has been appointed to carry out the photographic work required for the Laboratory, the Head Office, and some of the branches of the Department. A fair amount of the usual equipment as well as some photomicrographic apparatus is available, but recommendations have been made for a considerable expansion of equipment to provide for all types of work. A large amount of copying of documents, drawings, records, and charts was carried out during the year, as well as the making of prints from micro-films. Some photography was required in connection with laboratory tests, such as the weathering and wear of paints and the corrosion of metals. Photomicrography was undertaken in connection with investigations on metals and minerals. Spray Materials Spray work for the Plant Diseases Division dropped to a minimum. A few samples of New Zealand grown pyrethrum flowers and of derris dust were tested. The remainder of the work consisted of the testing of fresh importations of spray materials. Gas Inspection The gas-supplies of the four main centres and most of the other principal towns of the Dominion were regularly examined for calorific value, for pressure, and for freedom from sulphuretted hydrogen. It has again been found that difficulties were very generally experienced owing to shortage of coal and labour. This has resulted in many instances in failure to maintain the usual standards and even in complete failure of supplies of gas for short periods. The systematic testing of the accuracy of all gas-meters passed for service was carried out as usual,

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