PREFACE TO THIRD EDITIONTHE favourable reception accorded to previous editions by reviewers,students and practising organic chemists has encouraged the author toundertake an exhaustive revision of the entire text in the light of thenumerous developments in practical organic chemistry since the bookwas first written (1945-46). The net result has been an increase in thelength of the volume by some 150 pages, a figure which gives some indi-cation of the new matter incorporated in the present edition..