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It was found that certain samples of soda-lime that were high in silica gave very much inferior absorption of carbon dioxide when used in mine respirators than samples which were low in silica. For the Police Department the district laboratories and several sections of the Wellington laboratory made investigations, in addition to the toxicology mentioned earlier, of which instances were: paint fragments and horse-hair in " hit-and-run " cases; clothing that had been splashed and damaged in public places by an unknown liquid was found to be contaminated with hydrochloric acid containing tin; experiments on the detection of powder traces on wax casts that had been taken from the hands of a person suspected of having fired a pistol; glass fragments found on suspected persons, which were closely similar in physical properties to those found at the scenes of crimes; samples of alleged illicit spirits and articles and apparatus alleged to have been used in illicit distillation; ashes and other materials from two cases of alleged arson; a fraudulent so-called " radioactive" fly-spray; crystals, identified from a safe that had been opened by explosives; erased markings on metal objects and on clothing that were rendered legible by chemical treatment; and social-security stamps that were shown to have been used after removal of earlier cancellation marks. SERVICE TO INDUSTRY A great variety of problems of a chemical, chemical-engineering and bacteriological nature were investigated for manufacturing firms. A manufacturer of orange syrup was assisted in overcoming troubles due to fermentation. A patented process of egg-preservation was investigated for the patentee and for the Department of Industries and Commerce. Difficulties encountered in the manufacture of wax matches were looked into and the cause discovered. Fish-liver oils for export were certified as to vitamin A and vitamin D content. Many analyses were made for manufacturing firms especially of metals and alloys and in connection with corrosion problems. BACTERIOLOGY The bacteriological examination of milks and waters, which had been carried out for some years in the Christchurch district laboratory, was extended early in the year to Dunedin, and later to Auckland. Well-qualified bacteriological chemists are now on the staffs of each of the four laboratories. GAS-TESTING The gas-supplies of the four main centres and of most of the other main towns were regularly examined for calorific value, pressure, and freedom from sulphuretted hydrogen. All gas-meters put into service were tested and stamped before installation at consumers' premises. LIBRARY A comprehensive chemical and chemical-engineering library containing about 7,000 books and receiving over 200 scientific periodicals was efficiently run by a small staff of librarians, who provided the chemical staff with all the facilities expected from a modern library. During the year a " Recordak" microfilm viewer was obtained.

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