Describes an experiment that illustrates the role of hydrogen bond formation in producing a heat of reaction when ethanol and water are mixed. (MLH)

Describes a laboratory procedure for identifying carbon-14 labelled acetic acid by first converting it to acetophenone, then oxidizing the labelled carboxyl with permanganate. (MLH)

Describes a method for determining the rate constants of enzyme reactions involving two substrates with the use of double reciprocal plots. (MLH)

Describes a procedure for performing an enzyme assay colorimetrically on tyrosinase obtained from fruits and vegetables. (MLH)

Presents the views of the chairman of the group of scientists that prepared the preliminary proposal on DNA guidelines for the 1975 Asilomar Conference. Examples and illustrations are used to argue that stronger and tighter controls than those outlined in the National Institutes of Health (NIH) guidelines are needed. (CS)

Describes an experiment involving gas-liquid chromatography of fatty acid methyl esters in petroleum ether solution. (MLH)

Explores three classic turning points in science and presents close-up views of the scientists involved and their discoveries. Discussions include William Herschel and light; Lavoisier, Priestley, Scheele and oxygen; and Faraday and electromagnetism. Presents suggestions for experiments to demonstrate these discoveries. (JRH)

Purdue University (Indiana) is developing a series of computer modules of state-of-the-art chemical engineering processes to serve as the basis for computer-simulated experiments. One, sponsored by Procter and Gamble, models the extraction step in the decaffeination process and allows students to determine the optimal extraction conditions for…

Describes an approach to incorporating cooperative learning into the anatomy laboratory without diminishing the quality of instruction of the subject matter. Discusses the background, organization of groups and group tasks, evaluation of the approach, and potential disadvantages of cooperative learning. Contains 11 references. (JRH)

Describes experiments that illustrate a number of general principles such as pattern identification, displacement chromatography, and salting-out adsorption, plus an experiment that demonstrates that identification by chromatography alone is impossible. Illustrates that chromatography is still possible with quite simple means, notwithstanding the…

Presents activities that can be used to introduce thin-layer chromatography at the undergraduate level in relatively less developed countries and that can be performed with very simple and commonly available apparati in high schools and colleges. Activities include thin-layer chromatography with a test-tube, capillary feeder, burette, and rotating…

Describes a low-cost four-color LED photometer developed to overcome the rising cost of laboratory equipment used in general chemistry labs and introduce instrumentation at the undergraduate level. The photometer detects absorbance at selected wavelengths of visible light but retains the advantages of a dual-beam system. The unit is compact and…

Presents an interview protocol used to identify and evaluate students' conceptions of plants which is an invitation to participate in the third national study exploring elementary students' science conceptions. (YDS)

Found that in an introductory biology course at the University of Massachusetts Amherst, adoption of the Data Aggregation Project (free software that allows students in a course to aggregate a large body of data for some particular problem) resulted in an increase in the number of data points students analyzed per semester by a factor of almost…

A high school teacher's narrative of his engagement with Thoreau and experience of schooling explores themes in Thoreau's writing: experimentation, wholeness, and primacy of place. He uses these themes to critique contemporary educational practices, arguing against prescriptive teaching and for reexamination of all assumptions. (Contains 24…