...deposited, and capable of being removed by rubbing or the action of acid«. The position is thus arrived at, that radio-activity is at once an atomic phenomenon...change in which new kinds of matter are produced. Before such a view was entertained attempts made to explain it on existing hypotheses proved unsatisfactory....

...the change which gives rise to ThX produces a second type of matter decaying extremely slowly. - The radioactivity is at once an atomic phenomenon and...change in which new kinds of matter are produced. The atom is spontaneously breaking up with evolution of energy. A month after sending their second chemical...

...called transmutation, transformation, and disintegration) that they announced in 1902, they declared that "radioactivity is at once an atomic phenomenon...change, in which new kinds of matter are produced." The theory explained how the decay of radioactive atoms produces the transmutation of a parent into a daughter...