Reports on apparatus for generating Lissajous figures, projecting Poisson's spots, photographing diffraction patterns, electric heating, and projecting moving longitudinal waves on an oscilloscope. (SL)

A list of demonstrations of discrepant events which have been found to stimulate the curiosity of students in science at the secondary school level are presented. A brief description of the materials and procedures for 15 of these demonstrations is outlined, with short explanations of concepts and principles involved. (MP)

Described is a school project to investigate aggregations in flatworms which may be influenced by light intensity, temperature, and some form of chemical stimulus released by already aggregating flatworms. Such investigations could be adopted to suit many educational levels of science laboratory activities. (DS)

Presents the results of an experiment designed to test two hypotheses: (1) a delay of two weeks at room temperature will have no effect on the viability of fertile chicken eggs and (2) refrigeration will have no effect on the viability of fertile chicken eggs. Experimenters were the author and two ninth-grade students. (PEB)

Describes an apparatus for an experiment on winding motion in three dimensions. Discusses theory and provides a calculation example. (JM)

Presents a set of laboratory experiments that can assist students in the detection of carbon dioxide. Offers a variation of the supported drop method of carbon dioxide detection that provides readily visible positive results. Includes background information on carbon dioxide. (ML)

Describes a relatively simple method of extraction and purification of bacterial DNA. This technique permits advanced secondary-level science students to obtain adequate amounts of DNA from very small pellets of bacteria and to observe some of its polymer properties. (ML)

Directions for constructing a hand glider out of free or inexpensive materials are combined with measurements, tests and recordings of its flight done in metric units. (BR)

A two-part project involving critical thinking and writing skills focuses on a small crustacean and the scientific method. (Editor)

Examines the thermal decomposition of sodium bicarbonate to sodium carbonate. Encourages students to predict the end products and to use the stoichiometric results to determine if their predictions are correct. (MVL)

Methods are described for the induction and identification of respiratory deficient mutants in yeast. Practical schemes are given to enable students to obtain dose-response information for physical and chemical mutagens such as heat, ultraviolet light, or acriflavine. A simple test for environmental mutagens is described. (Author/MA)

Describes a simple method for measuring respiration, net photosynthesis, and compensation points of plants in relation to light intensity. Outlines how the method can be used in teaching physiological adaptation. Includes a set of the experiment's results. (ML)

Explores the selection, source, funding, time constraints, and community support involved in developing carefully planned and executed science projects. Lists 21 kinetics experiments noting the instrumentation needed and the original references. (MVL)

Describes ways to make use of lab activities and time for effective learning and student motivation. Provides information on the classification of lab activities, class data for measuring student power output, and a sample pre-lab "think sheet" activity. States the importance of relating activities to topics studied. (RT)

Reported are observational limits of detectability for several single stimulus and multi-stimuli observation tasks in secondary level chemistry. Provided are tables of actual results obtained including type of observation, chemical system used, method of determining stimulus magnitude, and observational thresholds. (Author/YP)