A Brief Account of Radio-activity

The text recounts early experimental discoveries that revealed spontaneous emissions from certain elements and distinguishes these radiations from other penetrating rays. It explains methods used to detect and measure ionization, photographic effects, and scintillations and classifies alpha, beta, and gamma components. The work presents evidence that alpha emissions are charged particles identified with helium and develops the disintegration theory to account for atomic structure and decay. It examines the energetic consequences of radioactivity, explains how emission alters atomic identities and positions in the periodic system, introduces isotopes, and surveys natural occurrences and measurement techniques while omitting complex mathematics.