Author provides details about Helmont's experiment that was a milestone in the history of plant biology since it marked the start of experimental plant physiology. Concludes that Jean Baptista van Helmont's supposedly simple experiment becomes complex when trying to determine the methods he used, evaluate his sources of experimental error, and…

Describes how microscale labs can be used as a tool to transform teaching instead of simply a less expensive substitute to traditional labs. Presents an activity that introduces students to density and the advantages of multiple measurements and averaging. (ZWH)

The ninth installment of the Science in a Box series (self-contained, hands-on activities for students grades three and up) presents activities for learning to use the sense of touch to determine how different objects conduct heat. All projects in the series are inexpensive and easy to assemble. (SM)

Describes the use of the Science Laboratory Environment Inventory (SLEI) which was designed for assessing senior science students' perceptions of aspects of their laboratory learning environment. Describes ways in which SLEI has been used in research studies and outlines ways educators could use the instrument for evaluating aspects of their own…

The loss of carbon dioxide from carbonated beverages provides an interesting case of the combination of equilibrium and kinetic principles. Adding air with a commercial device (the Fizz Keeper) has a negligible effect on various equilibria present but will slow diffusion in the gas space of a resealed bottle, decreasing the rate at which…

Discusses the need for long-term field experiments in undergraduate ecology curricula, and describes a field experiment in long-term succession set up to address this need. Reports on findings from the first year of the project. Contains 25 references. (WRM)

Identifies the development of practical and investigative skills featured in science qualifications at all levels (foundation, intermediate, and advanced) and all types (general, general vocational, and occupationally specific). Reviews the debate over the purpose of practical experimental work in science education and training. (Author/CCM)

Philosophers' attempts to convincingly explicate the received view of an ad hoc hypothesis--that it accounts for only the observations it was designed to account for--have been unsuccessful. Familiar and firmer criteria for evaluating the hypotheses or modified theories so classified are characteristically available. Contains 41 references.…

Presents samples of publicly available materials related to the role of iron in the diet. Summarizes what nutritionists feel about iron in the human diet and suggests some experiments related to iron for the classroom. (AIM)

Presents an experiment that tests for spontaneous generation, or abiogenesis. Observes microbial growth in nutrient broth under seven different flask environments. Includes instructions for the methods. (YDS)

Presents an overhead projector demonstration that uses the idea of color fading to demonstrate reaction kinetics and diffusion controlled reaction kinetics. (JRH)

Describes the experimental and theoretical details for constructing and calibrating an inexpensive, homemade liquid-lens refractometer. Measures refractive indices that are within the experimental errors discussed and close to the literature values. (JRH)

Describes systems used to introduce students to the concept of torque and discusses the effects that puzzle the beginner in the introductory lab. (JRH)

Describes a method to combine two learning experiences--optical physics and matrix mathematics--in a straightforward laboratory experiment that allows engineering/physics students to integrate a variety of learning insights and technical skills, including using lasers, studying refraction through thin lenses, applying concepts of matrix…