A short information on experimental knowledge of Curie husbands about radioactive substance obtained from uranite after separation of uranium, which they named Polonium, was the first notice on the progress in the research of radioactivity published in Listy Chemicke (October 1898). In further volumes of Listy Chemicke, a series followed of reference contributions about the pioneering works on radioactivity and the endeavour for finding and proving the existence of other naturally radioactive elements, namely polonium, radium, actinium, and radon.