William Ramsay's correspondence and papers, vol. 15: Work on radon with P. Whytlaw-Gray (part 1) Volume 15/1 of William Ramsay's correspondence and papers, as compiled by his former assistant, Morris W. Travers, following Ramsay's death. The contents of the volume are as follows: In the front of the volume: Photographs of Ramsay. Pages 1-54: Introduction. Pages 55-163: Correspondence and papers. (January 1910 – June 1911) Pages 96-107: R. Whytlaw-Gray and W. Ramsay, ‘Some physical properties of radium emanation’ (reprinted from ‘J. Chem. Soc.’ vol. 95, 1909). Page 108: R. Whytlaw-Gray and W. Ramsay, ‘The half-life period of radium: a correction’ (reprinted from ‘J. Chem. Soc.’ vol. 97, 1910). Pages 111-118: R. Whytlaw-Gray and Sir W. Ramsay, ‘The density of niton and the disintegration theory’ (reprinted from ‘Proceedings of the Royal Society’, series A, vol. 84, 1911). Pages 119-129: R. Whytlaw-Gray and Sir W. Ramsay, ‘The atomic weight of radium’ (reprinted from ‘Proceedings of the Royal Society’, series A, vol. 86, 1912). Pages 130-135: Manuscript on the work on niton of Ramsay and Whytlaw-Gray, included in the 4th edition of ‘Gases of the atmosphere’. Pages 136-144: Francis Lawry Usher, 'The influence of radium emanation on equilibrium in a gaseous system' (reprinted from ‘J. Chem. Soc.’, 1910). Pages 147-152: F.L. Usher: 'Die chemische Einzelwirkung und die chemische Gesamtwirkung der und B. Strahlen' (reprinted from 'Jahrbuch der Radioaktivität und Elektronik' vol. III, 3). Pages 153-154: F.L. Usher, ‘The influence of radium emanation on equilibrium in a gaseous system: a correction’ (reprinted from ‘J. Chem. Soc.’, 1910). 1910-[1957]