But it is apparent that our present knowledge of the elements stretches back into history: back to England's Ernest Rutherford, who in 1919 proved that, occasionally, when an alpha particle from radium strikes a nitrogen atom, either a proton or a hydrogen nucleus is ejected; to the Dane Niels Bohr and his 1913 idea of electron orbits; to a once unknown Swiss patent clerk, Albert Einstein, and his now famous theories; to Poland's Marie Curie who, in 1898, with her French husband Pierre laboriously isolated polonium and radium; back to the French scientist H. A. becquerel, who first discovered something he called a "spontaneous emission of penetrating rays from certain salts of uranium"; to the German physicist W. K. Roentgen and his discovery of x rays in 1895; and back still further.
"A Brief History of Element Discovery, Synthesis, and Analysis"
Glen W. Watson
This experience at least was as up-to-date as the Curies, becquerel, Ramsay, and the rest.
"Master Tales of Mystery, Volume 3"
Collected and Arranged by Francis J. Reynolds
Arago, F. Extracts from, in becquerel, Des Climate.
"The Earth as Modified by Human Action"
George P. Marsh