"Joliot was incontestably the first, in collaboration with Hans von Halban and Lew Kowarski, to prove that the fission of uranium atoms is accompanied or followed by an emission of neutrons - and subsequently that the fission of a uranium atom induced by one neutron produces, on the average, an emission of several neutrons..." (Dictionary of Scientific Biography, VII). In this important article, published six years prior to the detonation of the atomic bombs over Hiroshima and Nagasaki, "Halban, Joliot and Kowarski established the theoretical possibility of a self-perpetuating reaction chain... [though at the time] the only practical use suggested for it was implied in the Fermi patent for producing radioactive isotopes, which had been a continued blessing to medical and physiological research" (Printing and the Mind of Man, 422d). This issue of Nature also includes Lise Meitner and O. R. Frisch's seminal article, "Products of the Fission of the Uranium Nucleus." Meitner and Frisch played an important role in the development of nuclear fission, and included among their works are Printing and the Mind of Man 422b and 422c.