Describes an inexpensive, easy-to-construct manometric device that is a substitute for an expensive commercial transducer that is sensitive to slight pressure fluctuations. An activity for demonstrating the importance of CO-2 as a humoral regulator of respiration is described. (Author/SA)

Describes a physical chemistry experiment involving the analysis of the spectrum of benzene vapor in which the resolution in terms of wave length is a limiting factor. (CS)

He-Ne laser experiments suitable for an undergraduate laboratory are described. The topics covered are cavity stability, self-mode-locking coherent interactions between pulses and laser medium, and spontaneous transverse mode locking. (Author/DS)

Described is a gel diffusion experiment that permits the completion of duplicate diffusion runs within a three-hour laboratory session. Information included for the short-duration gel diffusion experiment is the diffusion cell, the experiment, data treatment, and the expected results of the experiment. (Author/DS)

Describes methods for studying heart primordia of the chick embryo, using the organ culture method. (CS)

Described is a school project to investigate aggregations in flatworms which may be influenced by light intensity, temperature, and some form of chemical stimulus released by already aggregating flatworms. Such investigations could be adopted to suit many educational levels of science laboratory activities. (DS)

The theoretical basis for the calculation of hydration numbers is developed. (BB)

Simple laboratory investigations are given which expose elementary students to optical crystallography techniques. Procedures and materials are designed for sixth-grade students. (SA)

The laboratory experiment described here is intended to be of use to the forensic science major enrolled in a course in organic chemistry. The experiment is the use of thin-layer chromotography for qualitative analysis, specifically for the identification of drugs. (Author/SA)

Presented here is a laboratory experiment for a course in physical chemistry. Students are requested to directly measure the degree of orientational order in a liquid crystal at room temperature. A minimum amount of equipment is necessary. (Author/SA)

Describes a typical relaxation kinetic experiment using a sudden increase in the temperature of the system. Time involved is described as minimal and the approach as quicker, more accurate, sensitive, and producing simultaneous determination of several thermodynamic parameters. (Author/SA)

Provides background relating cardiorespiratory disease to physical activity. Three laboratory activities are described: pulse response to posture change and quiet activity, pulse response to exercise (mild increasing to strenuous), and ability to extract oxygen. The last includes information on construction of an ergometer. (CS)

Describes an organic chemistry experiment for teaching the basic concepts of chemical kinetics. Provides background information about first- and second-order reactions, experimental procedures of the Diels-Alder reaction between cyclopentadiene and dimethyl fumarate, and the experimental results. (YP)