Symposium on Exchange—Introduction

THIS symposium consisted of a round-table discussion on exchange forces in ferromagnetics, and began with the presentation of invited papers by C. Zener, J. C. Slater, E. P. Wohlfarth (read by E. C. Stoner), and J. H. Van Vleck. A lengthy but lively discussion period, partly with the audience participating, followed the invited papers. It is unfortunately not possible to reproduce here the discussions, but R. Smoluchowski has been kind enough to prepare a brief summary and reconciliation of the invited papers: his discussion follows here after the papers.