Takeuchi Tokio's "Artificial Radium" : A Scientific Scandal in Early 1940s Japan

Abstract

This paper examines one of the most publicized scientific scandals in Japan before the end of　WWII, Takeuchi Tokioʼs alleged discovery of artificially induced radioactivity in common salt. In 1936, Takeuchi, then an associate professor at Tokyo Institute of Technology, claimed a discovery of　a new way to produce a radioactive substance. According to his paper, he could induce radioactivity in common salt by a gamma ray from a radium source. When Takeuchiʼs patent for this alleged　discovery was announced, Nishina Yoshio and other researchers at the Institute of Physical and　Chemical Research (RIKEN) objected. A debate took place at a monthly meeting of the Mathematico-Physical Society of Japan in June 1941. The controversy ended when Takeuchi and Nishikawa　Shōji conducted an experiment to confirm that Takeuchiʼs result was due to contamination from　the radium cells, and Takeuchi withdrew his patent. This incident attracted much media attention:　Newspapers and magazines published many articles on it. By examining the debates and the media coverage, this paper analyzes　how Nishina and other nuclear physicists sought to set a clear　boundary between acceptable and unacceptable studies of radioactivity, and shows that not only researchers, but also newspapers treated and demonstrated to the public the studies of radioactivity as something rationally verifiable, rather than magical or mysterious,　indicating that the relation　between the lay public and nuclear physics at that time was far more sophisticated than previously suggested. The paper concludes by discussing how such boundary work was possible in the given socio-cultural context.