Professor A. L. J. Beckwith is a foremost authority in the field of organic free radical chemistry. He has made a major Australian contribution to this field, and is undoubtedly a world authority in the subject. He has made a special study of the mechanisms of free radical reactions and the application of new discoveries in this field to general organic synthesis. His work on thiyl radicals, and radicals generated from lead tetraacetate and from organo-copper complexes is outstanding. Beckwith is also making important contributions to an understanding and application of free-radical rearrangement reactions.