Describes a laboratory exercise which applies Koch's Postulates to a plant disease, bacterial speck. Includes an explanation of Koch's Postulate, list of equipment needed, advance preparation, outline of the three-week activity, and variations of the laboratory exercise. (DS)

Describes (1) a rippler assembly which makes use of a loud speaker and a stroboscopic light source designed for this application; and (2) an experiment using a force table that has been modified for a capstan experiment. (JN)

Described are some experiments on geotropism that may be done using dandelions. (PB)

Provides physics teachers with comments on the value and role of demonstrations during lecture sessions. (SK)

Electronic energy levels in noble gas atoms may be determined with a simple teaching apparatus incorporating a resonance potentials tube in which the electron beam intensity is held constant. The resulting spectra are little inferior to those obtained by more elaborate electron-impact methods and complement optical emission spectra. (Author/SK)

Discusses the oscillatory motion of a mass on a spiral (nonhelical) spring, and calculates the lowest eigenfrequency and the associated effective spring mass for a range of values of the attached mass. Analytic and numerical comparisons are made to the helical spring problem. (HM)

Describes an undergraduate experiment which uses derivative spectroscopy to investigate the validity of the Planck function appearing in the blackbody radiation law. These measurements allow a critical examination of this function and also serve as an introduction to derivative spectroscopy techniques. (Author/HM)

Describes the use of a time-sharing computer and an x-y plotter in a variation of the laboratory exercise on the physical pendulum. (HM)

Describes a 9-hour organic chemistry experiment that involves the isolation of (+)-limonene from orange peels and conversion of this product into (-)-carvone. (CS)

Describes an advanced undergraduate laboratory experiment designed to give the senior chemistry student an opportunity to apply several synthetic and purification techniques as well as possibilities for the application of NMR spectroscopy. (CS)

When examining complex waveforms by examining oscillograms from simple resonant circuits, interpretation problems occur. These problematic oscillograms are explainable by recognizing that the typical resonant filters pass significant amounts of several harmonics adjacent to the one intended. Adjacent harmonics effects are computed; resulting…

Briefly refers to the history, physiological background, and adaptive implications of two theories concerning the limits of sensory discrimination. An experiment is described, suitable for college and high school students, which investigates the validity of the two theories. (CS)

Describes an apparatus that offers a very lucid demonstration of Poisson statistics as applied to electrical currents, and the manner in which such statistics account for shot noise when applied to macroscopic currents. The experiment described is intended for undergraduate physics students. (HM)

Presents two articles which are part of a series concerned with safety in school science in the United Kingdom. The two articles deal with restricted chemicals and experiments. (HM)

Describes the British Gypsum, a school-industry science project, designed to link the school with local industry. Teaching strategy, some experiments, and evaluation of the project are also included. (HM)