for the negative ions was accurately
, but for the positive ions it was
. From these results the conclusion was drawn that in X-ray ionization all of the positive ions are bivalent, i.e., presumably, that the act of ionization by X-rays consists in the detachment from a neutral molecule of two elementary electrical charges.
Fig. 11
Townsend accounted for the fact that his early experiments had not shown this high value of
for the positive ions by the assumption that by the time the doubly charged positive ions in these experiments had reached the tubes in which