In 1904 I published through the Cambridge University Press a collected account of radioactive phenomena entitled Radioactivity, followed a year later by a revised and enlarged edition. In 1912 a new volume was issued, entitled Radioactive Substances and their Radiations (Cambridge University Press), which endeavoured to give a concise account of our knowledge of radioactivity within the compass of a single volume.

The issue of this book was sold out soon after the conclusion of the War, and I was unable in the press of other work to find time for the preparation of a revised edition.

Since the publication in 1912, there has been a very rapid growth of our knowledge of the transformations of radioactive substances and of the radiations which accompany these transformations. The literature has rapidly expanded and many thousands of new papers, dealing with various aspects of the subject, have been published. It was felt that any attempt to give a collected account of the researches on this subject along the lines of the 1912 edition would have necessitated a very bulky volume. In the meantime, the need for such a publication had been met by the appearance of several new books. Professors Stefan Meyer and Egon v. Schweidler published, in 1916, Radioaktivität (Teubner, Berlin), followed in 1927 by a second enlarged edition. This excellent volume, which gives references to all the literature on this subject, is of great value to the scientific student. In 1928, Professor K. W. F. Kohlrausch published a collected account of radioactive researches entitled Radioaktivität, which appeared as one of the volumes of the Wien-Harms Handbuch der Experimental Physik.