Abstract
Careful measurements have been made of the ion content of air humidified by boiling water. A very sensitive cell of new design was used, having 40 parallel plates with a total area of 6.6×104 cm2 spaced 0.66 cm apart. A compensating cell with much smaller plates but with an identical insulator configuration was used to correct moist air conductivity data and to study insulator leakage. Results show that unexpectedly high concentrations of small ions (106–107/cm3) are present in air humidified by boiling water and that, in a closed container, a high ion concentration can be maintained for several hours after water vapor generation by boiling water has ceased.