A diffusion cell to model the permeation of salicylate drugs through the skin using low-cost materials and a sensitive colorimetric analytical technique is described. The diffusion apparatus has been used at a further education college by a student for her AS-level Extended Project to investigate the permeation rates of salicylic acid…

Short articles describe techniques for stroboscopic photography of moving objects, mechanical and electronic demonstrations of beats at radio frequencies, simple apparatus for the determination of the specific heat of steam, and the measurement of electrostatic potential by a flame probe. (AL)

Examines the controversy surrounding the validity and interpretation of electron microscope images. (DS)

Describes a means of collecting evolved gases which overcomes the usual disadvantages experienced in covering the electrodes with test tubes full of electrolyte solution. (GS)

Presents nine physics notes for British secondary school teachers. Some of these notes are: (1) speed of sound in a steel rod; (2) physics extracts-part four (1978); and (3) a graphical approach to acceleration. (HM)

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)

Describes the general features of three schemes used by teachers to assess their students' manipulative, observational, interpretational, and planning abilities and their attitude toward laboratory work. The three schemes were open-ended, intermediate, and check-list modes. A comparison of grades derived from these modes is presented. (GS)

Includes methods for determining melting and boiling points, illustrating the Finkelstein reaction, choosing acid-base indicators, growing perfect NaC1 cubes and "whiskers," bromination of alkenes, using vanadium in the laboratory, preparing phenylamine-copper (II) sulfate (VI) complex, simulating first-order chemical kinetics on a programmable…

Includes methods for demonstrating Schlieren effect, measuring refractive index, measuring acceleration, presenting concepts of optics, automatically recording weather, constructing apparaturs for sound experiments, using thermistor thermometers, using the 741 operational amplifier in analog computing, measuring inductance, electronically ringing…

Includes methods for using harmonographs in demonstrating motion of pendulums, constructing an electrostatic "bell," inverting mirror images, demonstrating the corrosion rate of steel, demonstrating expansion, studying rate of reaction between magnesium and hydrochloric acid, using matchboxes in science for containers, problem boxes, building…

Describes a number of simple experiments and demonstrations useful in secondary school science teaching. (AL)

Presents the following three biology notes: (1) a low cost variable temperature incubator; (2) projects on the ecology of freshwater mussels (Unionidae); and (3) studies on urease. (HM)