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lii a shooting case it was.found possible to calculate the approximate distance from which the shot was fired by the distribution of powder grains. In one case of burglary, chisel-marks on wood were found to correspond with a particular chisel and paint markings 011 the latter agreed with the three-coat paint system on the wood. A fatal case of poisoning was found to be due to accidental swallowing of tetraehlorethane, which was separated from the organs for identification by Ragsky's process. Christchurch.—ln specimens forwarded for toxicological examination, arsenic, oil of wintergreen (two), bismuth, chloroform, and alcohol were detected. Following the consumption of biscuits containing arsenic, two persons died and a considerable number of others were rendered seriously ill. An examination of the biscuits indicated that each contained J oz. of arsenic, which had been added in mistake for ground rice. Other exhibits included ether and ethyl chloride anaesthetics, blood and urine for alcohol content, and many liquor samples. Dunedin.—Barbitone was present in considerable amount in exhibits from a fatal case of poisoning. Other exhibits were examined for traces of alcohol, mainly in connection with fatal traffic accidents. The stomachs of poisoned opossums contained hydrocyanic acid. The baits which had apparently been used to poison them contained alkali carbonates but 110 trace of cyanide. Articles of clothing were examined for seminal stains. Mines Department The regular examination of large numbers of scheelite concentrates for tungsten and arsenic contents was continued throughout the year, and assays of ores for gold, silver, or other metals carried out as required. Mine airs and gases and stone dusts were analysed in connection with safety measures in coal-mines. Miscellaneous (prom other Departments) The variety of samples examined was too great to permit of mention of more than a few which were of special interest. These included boiler scales, boiler feed waters, and investigation of boiler-tube failures; comparison of various rust-proofing treatments on steel; lead-cable corrosion ; condenser electrolyte (analysis and preparation in bulk) ; mineral waters from Ngawha and Rotorua (with particular reference to boron and trace elements) ; fish-juice for salinity ; pigments for roofing-tiles ; syntheticrubber washers ; forsterite brick of local manufacture ; filter-stones (for durability in service) ; beeswax (development of a New Zealand Standard Specification) ; and silica gel of local manufacture for comparison with the imported article. Building Research Ever since the building of houses on a large scale was undertaken by the Housing Construction Department the Laboratory has been called upon to carry out examinations of many classes of building-materials and is the recognized testing authority for paints, roofing-materials, buildingbricks, and many other essential items. The main work carried out during the year comprised examination of concrete and clay roofing-tiles (including a survey to obtain data for preparation of a standard specification), testing of bricks, asbestos-cement products, enamelled sinks, copper supply tanks, cork insulating-board, paints, wood-preservatives, and wood-preservation investigations. 111 anticipation of a very greatly expanded housing programme in the post-war years, it was decided early in 1944 to send abroad two officers from the Laboratory staff to make a thorough study of recent developments in building-materials in Great Britain, Canada, and the United States of America, with particular reference to plastics, utilization of wood products, wood-preservation, fireproofing of wood, painting procedures, cement, and ceramics. After over a year abroad studying such problems, the two officers have now returned and the experience gained by them overseas will be invaluable to the Laboratory in its efforts to build up a Building Materials Research Section capable of giving a much better service to authorities concerned with housing construction and maintenance than has been possible. in the past. Ceramics Under the supervision of a Ceramic and Related Materials Research Committee the examination of raw materials for the ceramic industry was continued during the year. This work was carried out in close co-operation with Geological. Survey. Included among raw materials investigated wore fireclays and decomposed rhyolites from Mount Somers ; ball-clays from Kakaliu ; red-burning brick clays from Te Kuiti, Thames, Levin, and Kamo ; aluminous and pottery clays from Whangarei and other North Auckland districts ; processed clay washed from tertiary grit at Ligar Bay, Takaka ; fireclays from open-cut at Huntly and from Murchison ; bentonite from Porangahau ; serpentines for addition to superphosphate ; chalk from Oxford ; glass-sands from Mount Somers and Ross ; flints from Kaikoura ; feldspar from Charleston and elsewhere. For the State Forest Service limestones were tested for suitability for the manufacture of caustic soda for papermaking and advice given 011 white clay for paper filling. 111 view of the plans for increased activity in the construction of dams and other major works by the Public Works Department, it became necessary to carry out detailed examinations of Portland cements from the three cement companies. Cements and clinkers were tested not only for compliance with B.s. Specifications, but also for heat-evolution characteristics and alkali content. It is only recently that the importance of alkalies in cements has become realized, since it has been found by workers overseas that in some cases interaction between alkali and certain types of aggregate may take place, leading to serious deterioration of the concrete. Though 110 instances of such failure are known to have occurred in New Zealand, the position is being carefully watched and regular examinations of local brands of cement made. This work is being continued. During the year members of the staff engaged in ceramic work again had the opportunity of inspecting clay deposits and visiting potteries and cement-works.

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