Described are various methods for producing black and white photographs of microscope slides using single lens reflex, fixed lens, and plate cameras. Procedures for illumination, film processing, mounting, and projection are also discussed. A table of comparative film speeds is included. (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)

This article discusses training programs for environmental technicians at wastewater treatment facilities. Special attention is given to start-up orientation and training. (CS)

Suggested specifications for microscopes for various applications are given. A discussion of the ways of meeting these specifications in practice is illustrated by current models from British and foreign manufacturers. (BB)

Discusses a teaching program for introductory chemistry laboratories that allows for differences in student background and ability. The flexible program involves self-pacing and a classification of experiments; this permits slower students to proceed through remedial loops while advanced students proceed to more difficult experiments. (MLH)

Discusses the concept of educational efficiency of instructional methods, and suggests that although lab reports are effective learning tools, they are inefficient as an evaluation method. (MLH)

Describes two investigative labs that use live plants to illustrate important biological principles, include quantitative analysis, and require very little equipment. Each lab is adaptable to a variety of class sizes, course contents, and student backgrounds. Topics include the evolution of flower size in Mimulus and pollination of Brassicas. (DDR)

Presents two simple and reliable ways for measuring protease activity that can be used for a variety of investigations in a range of biology class levels. The investigations use protease from a variety of sources. (DDR)

Discusses processes for change that have been used to introduce innovative learning processes into laboratory courses. In one case the content of the course was not changed, just the order of presentation. In the second example cooperative learning processes were introduced in order to facilitate a change in the course content. (AIM)

Described is an activity in which the life cycle of a plant is investigated over a 20-day period. Included are background information, a list of materials, procedures, diagrams of the plant, apparatus, and pollination. An outline is suggested. (CW)

Outlines procedures for demonstrating and preparing a permanent slide of sister chromatid exchanges and recombination events between the two chromatids of a single chromosome. Provides the name of an additional resource for making preparations of exchanges. (RT)

Provides specific procedures for the disposal of a variety of highly reactive chemicals and reports the results of a study of their safe disposal. Disposal of some problematic sulfur-containing compounds are included. Procedures are based on a combination of literature review and author development. (LZ)

Describes a simple method for preserving snowflakes that allows them to be viewed and photographed through a microscope under different lighting and color-filtering systems to bring out details that would otherwise go unnoticed. Includes directions for preparing the preserving solution, replicating procedures, and the related safety precautions.…

A quantitative and inexpensive way to measure the rate of enzymatic reaction is provided. The effects of different pH levels on the reaction rate of an enzyme from yeast are investigated and the results graphed. Background information, a list of needed materials, directions for preparing solutions, procedure, and results and discussion are…

The study of aerodynamics using a wind tunnel helps students develop an understanding of the basic scientific concepts of lift, drag, and stability and their applications. Directions for building a wind tunnel in the classroom and activities for using the tunnel are provided. (KR)