Presents an activity to determine whether the radioactivity of a pure potassium salt is directly proportional to the amount of potassium in it and whether this could be used as a method of analysis for potassium in a solid. (MKR)

Presents experiments that use Helmholtz resonators and have been designed for a sophomore-level course in oscillations and waves. Discusses the theory of the Helmholtz resonator and resonance curves. (JRH)

Describes how burying beetles can be used to explore conflicts between breeding individuals. Discusses conflict over the ownership of the resource and of the breeding group. (JRH)

Describes a laboratory exercise used by botany students to verify their textbook's teaching about photosynthesis and respiration. (ZWH)

Describes an inexpensive replacement for the gel matrix, agarose, to aid teachers in reducing the cost of supplies needed to perform gel electrophoresis experiments. (ZWH)

Discusses an analysis of the relationship of soil temperatures at 3 depths to various climatic variables along a 200-kilometer transect in west-central Oklahoma. Reports that temperature readings increased from east to west. Concludes that temperature variations were explained by a combination of spatial, temporal, and biophysical factors. (SG)

Explored is the role of thought experiments in the development of physical theories. Drawing examples from quantum theory it asks how a method that generates no new empirical data can nonetheless exert an influence upon a subject defined by its empiricism. (Author/KR)

Describes a simple way for groups to view a demonstration of Brownian Motion using a laser and liquid suspension. (AIM)

Describes a combination of solutions that can be used in the study of kinetics using the iodine clock reaction. The combination slows down degradation of the prepared solutions and can be used successfully for several weeks. (JRH)

Discusses some of the important characteristics of fungi. Presents exercises designed to introduce students to factors influencing the development of mushroom fruiting bodies. (JRH)

Discusses the behavior of the current near the end of the paper in the electric-field mapping experiment and approaches to solving problems associated with this behavior. Presents programs that can be used to model the boundary condition computationally. (JRH)

Describes an experiment to measure the speed of air in the air jet caused by blowing air through a drinking straw. (JRH)

Describes a diffraction experiment that uses circular holes salvaged from nonaerosol hair spray bottles to produce spectacular circular interference fringes. (JRH)

Presents a model experiment for quantifying phagocytosis using earthworm coelomocytes and determining the optimum length of time necessary to obtain maximum phagocytosis. Involves incubating coelomocytes from invertebrates with an antigen, staining the cells, counting the number of antigen particles ingested, and measuring the effect of different…

Describes the preparation of a simple microbiological medium using inexpensive materials routinely available in any supermarket. Discusses inoculation of the medium and colony examination. (JRH)