An experimental system, suitable for secondary schools, uses Chlorella vulgaris to demonstrate the effects of mercury and cadmium. Very low concentrations of mercury or cadmium decrease growth, whereas lead or arsenic have little effect. Further experiments show additive interactions between mercury and cadmium and antagonistic interactions…

This article looks at the problems of revision of laboratory courses. While revision of the syllabus of experiments is expensive, it is necessary to keep it up to date. The nature, causes, and rates of change in practical courses are discussed. (BB)

Describes an experiment that has been introduced in the organic chemistry laboratory program at Shepherd College, Shepherdstown, West Virginia. It illustrates microbial reaction and its role in the synthesis of vitamin C. (HM)

Presents a biochemistry experiment for college students that illustrates the purification of an enzyme. (HM)

Principles, experimental procedures, results, and discussion of this method are included here. The method was used in undergraduate laboratory courses in Toulouse, France. (BB)

Presents details of demonstrations illustrating cathodic protection using a photovoltaic source and optical rotation. (SL)

Described is the use of molecular model kits in high school biology class and gives a laboratory unit for studying molecular structures of fats, proteins, and carbohydrates. (BB)

Reviews legislation and controls in effect, and needed, to reduce the hazards of violent reactions in the uncontrolled mixing of incompatible chemicals. (SL)

Use of graphs in studying greatest common divisors, least common multiples, and other concepts can illustrate patterns related to the definitions of these concepts. (SD)

Describes techniques for studying hand specimens of polished rock slabs. (SL)

Media is used as a supplement in a science education program based on the inquiry method. Students work in small groups and rotate from station to station. (STS)

Includes procedures for demonstrating anaerobic respiration in peas, isolating virgin Drosophila females, solving mortality problems in young gerbils, measuring dissolved oxygen, constructing models for transpiration and DNA molecules, freezing chick embryos, mixing nutrient media, illustrating Darwinian ecological principles, and detecting…

A science program in which students were encouraged to select their own project goal as well as the apparatus to accomplish this goal was developed and tried in two 5th grade classes. (Author)

Presented is the development of a simulation model of the facultative water transfer mechanism of the mammalian kidney. Discussion topics include simulation philosophy, simulation facilities, the model, and programming the model as a teaching aid. Graphs illustrate typical program displays. A listing of references concludes the article. (MA)

Proposes that identification keys provide an orderly strategy for the identification of igneous and metamorphic rocks in an introductory geology course. Explains the format employed in the system and includes the actual key guides for both igneous and metamorphic rocks. (ML)