The mobility of ions in air.- Part I. Negative ions in moist air

The mobility of “small” ions at atmospheric pressure and temperature has been the subject of investigation at intervals for more than a quarter of a century, and one would have imagined that unanimity of opinion on the numerical values would have been reached in the case of the commoner gases. And yet this is by no means the case. In the case of negative ions in air, with which the present paper is concerned, there is wide disagreement between the values obtained for the mobility by different observers, and it is disputed whether the ions are all of the same mobility or are distributed in groups of several different mobilities.