Describes an experiment that emphasizes the discrete nature of the different oxidation states of vanadium by the separation of ammonium metavanadate into all four species by ion exchange chromatography. (CS)

A laboratory exercise for dental students is presented using a toxic dose of lidocaine in place of an anesthetic dose of pentobarbital. The use of lidocaine demonstrates its toxic and lethal actions and increases the relevance of the experience for dental students. (Author/MLW)

Outlined are simple activities for studying soil, which can be conducted in the schoolyard. Concepts include soil profiles, topsoil, soil sizes, making soil, erosion, slope, and water absorption. (SJL)

Describes experiments intended to produce a better understanding of the holographic method of producing images and optical imaging by other optical systems. Application of holography to teaching physics courses is considered. (Author/SA)

Explains how to demonstrate the following: the hysteresis effect and the existence of domains in Rochelle salt (sodium potassium tartrate); diffraction experiments using a slide with multiple slits; and an analogue technique for learning terminal velocity. (GA)

Describes and explains some aspects of the motion of a top, the extreme end of which is made round, spinning on surfaces provided with friction. (Author/GA)

A discussion of Edwin Land's experiments with color images from black-and-white photographs. Information is presented for duplication of these experiments by the amateur photographer. (BB)

Discusses the existence of spirals in nature in general, supplying many examples, and explains how a particular organism, Phycomyces, accomplishes this feat. (GA)

Describes the following: a low-pressure sodium light source; a design of hot cathodes for plasma and electron physics experiments; a demonstration cart for a physics of sound course; Bernoulli force using coffee cups; a spark recording for the linear air track; and a demonstration of the effect of altering the cavity resonance of a violin. (GA)

Explains how to use glass tubing to form a simple microscope; how to construct an over-voltage protection circuit; and how to demonstrate electromagnetic effects with a coil and rubber bands. (GA)

An activity is described that is designed to give students a chance to learn about speed by calculating their own running or walking speed and the speed of cars. (MP)

Discusses the determination of the position of the absorption maximum in wide bands as well as the confidence limits for such calculations. A simple method, suited for pocket calculators, for the numerical evaluation of these calculations is presented. (BB)

Describes process-based practical work used in Scottish high school examinations and evaluates this work against a standard of course objectives for practical work in general. (MLH)

Discusses how students can investigate the relationship between the current and the voltage across a field coil by using a current that has a triangular waveform. (MLH)

Three experiments, employing conditioned suppression in rats, examined the extent to which pretraining on one element of a compound stimulus blocked conditioning to the other element when some feature of the reinforcer was changed on compound trials. (Editor)