Chemistry is a subject experiencing very rapid growth. New areas of researeh are opened and new methods are developed with a speed whieh must seem impressive. The pieture has, however, another side represented by the great number of unsolved or poorly solved problems left behind when a branch of chemistry is no longer fashionable. When three years ago I beg;m to plan this book I felt that the molecular adduets of oxo compounos constituted just sueh a field of research, and that they might acquire greater interest if approached from the standpoint of modern chemistry. The developments of the...