Masataka Ogawa was a Japanese chemist known for the discovery of rhenium, which he named nipponium.
After graduating from the University of Tokyo, he studied under William Ramsay in London, where he worked on the analysis of the rare mineral thorianite.
He extracted and isolated a small amount of an apparently unknown substance from the mineral, which he announced as the discovery of element 43, naming the newly discovered element nipponium. He published his results in 1909 and a notice was also published in the Journal of the American Chemical Society. However, no other researchers were able to replicate his discovery, and the announcement was forgotten.\r\nRecent research has indicated that whilst he did not identify element 43 (finally isolated in 1937 by an Italian group), he had apparently isolated element 75, rhenium, which would not otherwise be successfully identified until 1925.
Ogawa served as president of Tohoku University between 1919 and 1928.