Discusses Jacobus Henricus van't Hoff's revolutionary theory of the asymmetric carbon atom and its early reception among his contemporaries in the Netherlands. Indicates that the extension of the new idea to practical problems gives the impetus to the development of stereochemistry. (CC)

Presents fundamentals of the glassy state which can serve as an introductory, phenomenological, and nonmathematical exposure to undergraduates in at most two lectures. Suggests the use of the material following students' acquisition of an elementary knowledge of thermodynamics, liquids, and the crystalline state. (CC)

Discusses the flow characteristics of thixotropic and negative thixotropic fluids; various theories underlying the thixotropic behavior; and thixotropic phenomena exhibited in drilling muds, commercial paints, pastes, and greases. Inconsistencies in the terminology used to label time dependent effects are revealed. (CC)

Discusses the origin of de Broglie's concept and its influences on his contemporaries, notably on Einstein, Schrodinger, Elsasser, Davisson, and Thomson. Indicates that the theory served not only as the starting point of quantum mechanics, but also opened new experimental possibilities. Historical inaccuracies are corrected with new material…

Discusses theories underlying the phenomena of solution viscosities, involving the Jones and Dole equation, B-coefficient determination, and flickering cluster model. Indicates that viscosity measurements provide a basis for the study of the structural effects of ions in aqueous solutions and are applicable in teaching high school chemistry. (CC)

Examines aspects of competitive exclusion, which develops when two species jointly utilize a vital resource that is in short supply. When this occurs, one of the species will eventually eliminate the other from the habitat where their distributions overlap, unless one or both species evolve differences that reduce competition. (JR)

Discusses the use of a balance assembled from standard laboratory components to conduct an experiment on the repulsion between two bar magnets. Includes an analysis of data on the two-pole and four-pole models. (CC)