A new method of carrying out grafts of early embryonic chick limb buds to the chick chorio-allantoic membrane and a processing schedule which renders cartilage elements visible in whole mount are discussed, including implications for the procedures and their results. (Author/DC)

An experiment on the operation and utility of an amperometric immobilized enzyme electrode (or probe) is described, including advantages of the experiment, equipment, reagents, preparation of phosphate buffer, enzyme immobilization techniques, laboratory procedures, precautions, and discussion of experimental results. (SK)

Crushed glass and a Rhodamine B solution are used in a one-dimensional optically scanned column experiment to study the dispersion phenomenon in porous media. Results indicate that the described model gave satisfactory results and that the dispersion process in this experiment is basically convective. (DC)

Provides background information and problems with the formaldehyde clock reaction, including comparisons of experimental clock times reported in the literature and conditions for the reliable use of the formaldehyde clock based on a method discussed. (JN)

A series of learning cycle laboratory experiments for general chemistry was developed. The exploration, invention, and application phases of one cycle related to calorimetric measurements are described. (Author/SK)

Describes an inexpensive, low-pressure liquid chromatography pump, slurry filler, stainless steel columns, and injector system suitable for the undergraduate laboratory or routine analysis. Includes sectional diagram of the pump and construction diagram of the preparative columns. (Author/SK)

Experimental procedures are provided for the quantitative determination of Vitamin A (retinol) in food products by analytical liquid chromatography. Standard addition and calibration curve extraction methods are outlined. (SK)

Materials and methods are presented illustrating a modification of the Nakai/Glinsmann technique for comparing apparent formation constants for ADP-Mg and ADP-polyamine complexes. (Author/SK)

Describes experiment expanding on principles behind measuring efficiency of chromatographic columns and allowing calculation of parameters in the van Deemter equation. Easily accomplished in a three-hour period using a gas chromatograph in which gas flow can be changed and measured. Mathematical solutions can be attained with programmable…

An experiment using gas-liquid chromatography is discussed, introducing the student to concept of dead volume and its measurement, idea and use of an internal reference compound, and to linear relationship existing between measurements of a separation on two different stationary phases. (Author/SK)

The use of a logarithmic amplifier preceding an oscilloscope's vertical amplifier is described for physics teachers who want to demonstrate the exponential decay nature of some phenomena. (Author/SA)

Intended for the elementary teacher who lacks science teaching experience, this article presents tips for finding background information and for stocking a portable "science lab" with everyday materials. It also outlines 10 easy experiments. (SJL)

Compares and contrasts effects of two spectroscopic techniques on bromine and iodine vapor. (CS)

Presents two experimental set-ups. The first demonstrates the law of Malus using a pair of Polaroid polarizers and a monochromatic light source with an interference filter. The second describes a modification of Hilton's apparatus to demonstrate the effects of the magnetic hysteresis on an overhead projector. (CS)

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)