Describes an experiment (carried out in less than two hours) in which the merits of countercurrent extraction are immediately evident by visible colors. The experiment requires eight 125-ml separatory funnels, 250ml of 1-butanol, 250ml of 0.1-0.5 molar hydrochloric acid, and a small amount of Sheaffer's Skrip blue-black soluble ink. (JN)

Discusses investigations of mirages with an astronomical telescope and a way of demonstrating three of the main features of laser/maser action. Also discusses several physics demonstrations using color television. These include thin-film interference effects, single-slit diffraction, emission/absorption spectra, "rings and brushes"…

Explains interference colors in thin films as being due to the removal, or considerable reduction, of a certain color by destructive inteference that results in the complementary color being seen. (GA)

Although indicators are omnipresent tools in aqueous chemistry, they have not been used extensively to assign solvent properties in nonaqueous systems. Therefore, recent research into a system of metal complexes that can be used to assign donor and acceptor numbers to nonaqueous solvents is summarized. Pertinent experiments are also described. (JN)

The separation by high performance liquid chromatography of five common dyes from foods containing "artificial color" is described. (CS)

Presented are procedures for demonstrating the production of color oscillations when nitric acid is added to a formic acid/concentrated sulfuric acid mixture. Because of safety considerations, "Super-8" home movie of the color changes was found to be satisfactory for demonstration purposes. (JN)

Artists use red, yellow, and blue as primary colors, whereas physicists use red, green, and blue. Explains the reason using the spectra of mixtures of red, green, blue, and yellow tempera obtained with a Carey spectrophotometer. (GA)

Describes a system that demonstrates how a color may be generated and specified in mathematical terms. Illustrates the mixing of primary colors as well as the concepts of saturation, luminance, and illumination. (JRH)

Several activities related to color are discussed. These include placing different colors on a disk which, while spinning, appears to be white. Also discusses complementary and primary colors. (JN)

Reports on the colors observed during titrations of 15 natural indicators obtained from common fruits and vegetables. These edible indicators can be used for a variety of teacher demonstrations or for simple student experiments. (JN)

A simple device used to demonstrate the main features of primary color addition is described. Materials needed to construct the device, procedures used, and typical results are discussed. (JN)

Describes an experiment enabling students to apply concept of diffraction, determine limits of their color perception, learn how to measure wavelength with a simple apparatus, observe continuous and line spectra, and associate colors with corresponding wavelengths. The homemade diffraction-grating spectrometer used is easily constructed. (JN)

Information related to the history of optics with emphasis on the classical and medieval periods is presented. Notes are included on experiments dealing with refraction at a plane interface between two media; refraction by transparent spheres; light, color, and reflection by transparent spheres. (Author/SA)

The life and work of Isaac Newton and his investigations of light and color are described in detail. Notes include preliminary observations of chromatic dispersion; dispersion by an equilateral prism; the "Experimentum Crucos" or the composite nature of white light; the nature of colored light and illumination; transmissions and…

Describes how color graphics are built up on microcomputer displays and how a range of colors can be produced. Discusses the logic of color formation, noting that adding/subtracting color can be conveniently demonstrated. Color generating techniques in physics (resistor color coding and continuous spectrum production) are given with program…