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)

This experiment subjects bacteria in a food sample and an environmental sample to conditions of sublethal stress in order to assess the effectiveness of the agar overlay method to recover sublethally injured cells compared to direct plating onto the appropriate selective medium. (SAH)

Describes the construction and use of an inexpensive colorimeter that reliably estimates the phosphorus concentrations in water. Presents a two-step modification to an existing photometer. (SAH)

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

Describes a laboratory course that introduces students to chemistry using examples commonly encountered in the supermarket and on the dinner table. Acquaints students with simple chemical tasks that can be practiced at home, including the making of wine, ale, soap, cheese, and yogurt, and introduces them to the small-scale production of…

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)