Detailed instructions for the construction of apparatus to detect qualitatively the production of carbon dioxide by respiring organisms are given, with notes on its use and comments on its advantages compared with traditional equipment. The chemistry section of the bulletin contains the results of tests of the efficiency of several laboratory burners designed for use with Liquified Petroleum Gas and recommendations of the brands most suitable for use in Scottish Schools. A list of surplus physics apparatus available for purchase, by Scottish Schools, from the Scottish Schools Science Equipment Research Centre is included, and a supplement lists recommended biology apparatus. (AL)