Factors Affecting the Nature of Ions in Air

This paper embodies the results of an attempt to determine some of the conditions which affect the nature of ions in air. It is shown that drying agents like Ca${\mathrm{Cl}}_2$ and ${\mathrm{P}}_2$ ${\mathrm{O}}_5$ are not sufficient for drying purposes and that cooling by means of liquid air is essential for the more complete results. In air dried in this manner the initial positive ion transforms into the final ion very slowly, if at all. Results are also given confirming Tyndall, Grindley and Sheppard, that the ionizing process itself gives rise to impurities affecting the ions. It is shown that the effect of water is modified by the presence of the impurities due to ionization. The requirements essential in any method for the study of ions are given at the close of the paper.