This is a review of important science news stories of 1990 as reported in the pages of this journal. Areas covered include anthropology, astronomy, behavior, biology, biomedicine, chemistry, computers and math, earth sciences, environment, food science, materials science, paleobiology, physics, science and society, and space sciences. (CW)

Presented is a demonstration of magnetostatic image poles in the presence of ferromagnetic materials. The experimental set up and probable results are discussed. Real and image systems are illustrated. (CW)

Presented is an experiment in which students recover almost 90 percent of the original lead chloride thus saving on costs of chemicals and disposal. Included are experimental procedures and a discussion of typical results. (CW)

Discussed is the preparation of synthetic brochantite from solution and a thermogravimetric-differential thermal analysis study of the thermal decomposition of this compound. Other analyses included are chemical analysis and IR spectroscopy. Experimental procedures and results are presented. (CW)

Described is the derivation of the relationship between the pH measurement error and the resulting percentage error in hydrogen ion concentration including the use of variable activity coefficients. The relative influence of the ionic strength of the solution on the percentage error is shown. (CW)

Described is an activity in which the interactions between a parasite and its host may be demonstrated using the relationship between yogurt and two species of bacteria. Background information on Koch's postulates is provided. Materials, laboratory procedures, and results are discussed. (CW)

Reported are the results of a survey of the economic status of members of the American Chemical Society. Included are employment, salaries, satisfaction, and the status of women in chemical occupations. (CW)

Methodology which can be used to evaluate cyclic trends in sequential data are discussed. Examples and suggestions for teaching using this method are provided. A list of 25 references is included. (CW)

Outlined is a method for collecting and cutting oriented samples for microstructural analysis including handling the samples in the laboratory, cutting and orienting chips parallel to the motion plane, and cutting and orienting chips normal to Le and foliation. (CW)

Presented is an interpretation of the inward and outward growth and formation of plume textured geodes available from southern Brazil. Field occurrence, morphology of vesicles, growth history, closure of the agate shell, microscopic features, coherent reflection of light from convoluted surfaces, and accessory minerals of the inner cavity are…

The design and data management of an activity to study weathering by increasing the rate of mineral dissolution in a microwave oven is described. Data analysis in terms of parabolic and first-order kinetics is discussed. (CW)

Features of Crassulacean Acid Metabolism plants are presented. Investigations of a complex eco-physiological plant adaptation to the problems of growth in an arid environment are discussed. Materials and procedures for these investigations are described. (CW)

Presented is an approach to solving oxidation-reduction reactions. The advantage of this procedure for both acidic and basic equations is stressed and emphasizes the electrical nature of redox equations. (KR)

Discussed is a series of lectures designed to illustrate the use of general organic chemical principles in molecular biology, introduce current research in interdisciplinary areas to the beginner, increase interest in organic chemistry, and bridge the gap between traditional organic chemistry, biology, and the consumer. An outline is presented.…

Reviewed is the use of the Thin-Film Mercury Electrode for anodic stripping voltammetry, simple voltammetry of solution cations and cathodic stripping voltammetry for the determination of an environmentally important molecule, thiourea. The construction of a simple potentiostat and applications for student laboratory courses are included. (CW)