The mobility of ions in air. Part.V―The transformation of positive ions at short ages

It was shown in Part IV of this paper that both the methods there described, which involved the use of closed vessels, gave variable results for the rate of transformation of positive ions, and values of the rate which were higher than those obtained by Erikson or by Tyndall and Grindley. It was felt that this might be due in part at least to products of chemical action arising from the α-rays, or to the impurities given off from the wails which would accumulate in a closed vessel unless some agent is present to remove them. To investigate this possibility further, the writers set up an air-blast method in which the effect of adding or taking away such impurities could be conveniently studied.