In his paper ‘The Gibbs Paradox and the Distinguishability of physical Systems’ (this Journal, July 1964) Robert Rosen discusses the discontinuity of the diffusion entropy S of two gases, A and B.

Professor Boring is best known for his work in the history of psychology and for good reason: his History of Experimental Psychology and his Sensation and Perception in the History of Experimental Psychology are truly impressive works. However, he has also written numerous articles in the philosophy of science, the psychology of scientific discovery, and the sociology of scientific production, but unfortunately this material has not heretofore been readily accessible. This deficiency, however, has been corrected efficiently by the recent publication of Boring's History, Psychology, and Science: Selected Papers, edited by Robert I. Watson and Donald T. Campbell. The essays in this book represent the whole range of Boring's interests and make essential reading for any serious student of the philosophy of science. Of especial value to philosophers are the essays listed under the titles “The Scientific Method” and “The Mind-Body Problem.” Since the groupings overlap, however, the following essays in other categories are also crucial: “The Nature and History of Experimental Control,” “William James and the Psychology of the Present,” and “The Influence of Evolutionary Theory Upon American Psychological Thought.” All of these essays are interesting but the ones on operationism and theory in psychology, and the one on evolutionary notions in American psychology, are classics and worth very careful consideration and comment.