Points from Foregoing Letters

Abstract

FOLLOWING upon Hahn and Strassmann's observation that isotopes of barium are probably formed when uranium is bombarded with neutrons, Prof. Lise Meitner and Dr. O. R. Frisch discuss a new type of nuclear reaction in which a heavy atomic nucleus after taking up a neutron splits into two roughly equal nuclei, very much as a drop of water breaks into two when its size is large and its surface tension is low. In the case of uranium, if one of the new atoms formed is barium the other will be krypton. Thorium apparently breaks up into barium and lanthanum isotopes.