Suggests that the Friedel-Crafts reaction, used for synthesizing a wide range of aromatic compounds, is an ideal vehicle for extended senior high school project work in chemistry. Provides a theoretical discussion of the reaction, suggests a number of suitable investigations, and outlines the experimental details. (JR)

Analyzes the role of experiments in science teaching, and applies this analysis to the teaching of Millikan's experiment in physics. Critically examines an article written by T. J. Harvey entitled Millikan made easy'' which was previously published in The School Science Review. (JR)

Describes a demonstration experiment designed to estimate the equilibrium constant by comparing the conductivities of acetic and hydrochloric acids. (CC)

Describes a course based on laboratory use of three skills as a way of teaching a general method of problem solving. (DF)

An experiment involving the preservation of mouse kidney cortex and liver tissues is set up to evaluate the relative tonicity of fixatives. (DF)

A laboratory demonstration is suggested for the formation of a-amylase enzyme in halved grains of barley. Data presented in the article provide some information of the pattern of a- and b-amylase activity during germination. (PS)

Describes an experiment for the intermediate undergraduate optics laboratory designed to illustrate simultaneously some aspects of the phenomena of diffraction; interference, coherence, apodization, the Fresnel-Arago law; as well as of the interrelations between these concepts. (HM)