Provides a method for correcting the photoemission from a collector when using the photoelectric effect experiment to determine Planck's constant. The problem results from a negative current through the cell and makes the measurement of the cutoff potential difficult. (DH)

Traces the history of the antivivisection movement, examining issues related to the use of animals in studying the cause of rabies. Also discusses issues related to the current controversy over animal experimentation. (JN)

Provides an overview on biological electron-transfer reactions, summarizing what is known about how distance, spatial organization, medium, and other factors affect electron transfer. Experimental approaches, including studies of bimolecular electron transfer reactions (electrostatic effects and precursor complexes), are considered. (JN)

Provides the rationale for and examples of experiments designed to test the stability of protons and bound neutrons. Also considers the unification question, cosmological implications, current and future detectors, and current status of knowledge on proton decay. (JN)

Suggests using better materials in fire syringes to obtain more effective results during demonstrations which show the elevation in temperature upon a very rapid (adiabatic) compression of air. Also describes an experiment (using ignition temperatures) which introduces students to the use of thermocouples for high temperature measurements. (DH)

Presents a nonmathematical approach to help students understand that there are two types of coherence and to associate coherence as a property of the illumination at an object itself. The approach also lends itself to an introduction to the Fourier approach for analyzing imaging systems. (JN)

Appraises current explanations of how visual processing occurs. Highlights the basics of simultaneous and serial levels of processing. Discusses the results of a series of experiments on visual-search tasks and also on the role of prior knowledge in processing. (ML)

Describes experiments which focus on the perception of three dimensions. Discusses the cues about distance and depth and the role they have in perceptions of three dimensions. Evaluates the effect of color on the illusion on depth. (ML)

Discusses the development of the concept of atomicity and some of the many which can be used to establish its validity. Chemical evidence, evidence from crystals, Faraday's law of electrolysis, and Avogadro's number are among the areas which show how the concept originally developed from a purely philosophical idea. (JN)

Presents research results on photosynthetic, carbon monoxide utilizing bacteria. Discusses applications of the research and offers three sets of experimental procedures and data that students analyze to determine which bacterium from a soil sample uses carbon monoxide fastest. (Contains 21 references.) (MDH)

This article reports the adoption of new policies to restrict experiments on animals in the elementary or secondary school classroom. The controversy involving animal welfare groups is discussed as it relates to animal abuse by students. (SA)

Provides a running commentary on a chemistry instructor's first day in a first course in chemistry. Focuses on the use of fire and chemists' attempts to explain this phenomenon. Provides the ongoing descriptions of the experiments, a summary of the observations, and the key comments made by the instructor. (TW)