The Mobility of the Ions of the Active Deposits of Thorium and Radium

The method used is the same as in a similar study of the active deposit of ${\mathrm{actinium}}^1$. As in the case of actinium, two positive active bodies differing in mobility were found in the active deposits of thorium and radium. In the case of these three deposits, all of the three swifter bodies have equal mobilities in air, and, likewise, all of the three slower bodies. The curves obtained indicate that one of the active bodies is not deposited as an A product and the other as a B product; nor is one ion atomic and the other polyatomic. It is believed, however, that one is singly and the other doubly charged.