The English chemist Frederick Soddy (1877-1956) shared in the discoveries of atomic disintegration and of helium production during radioactive decay and introduced the term "isotope" to nuclear science.

Frederick Soddy was born at Eastbourne, Sussex, on Sept. 2, 1877. He studied at Eastbourne College; University College, Aberystwyth; and Merton College, Oxford, where in 1898 he received his degree in chemistry.

Radioactivity Studies at Montreal

Having accepted a demonstratorship in chemistry at McGill University, Montreal, Soddy found himself increasingly attracted by the work being done by Ernest Rutherford, then research professor of physics at the university. He joined Rutherford's team and brought to it his valuable experience as a chemist.

In a study of the radioactivity of thorium, Rutherford and Soddy added ammonia to a solution of a thorium salt, so precipitating out thorium hydroxide. When the insoluble material had been filtered off, the remaining solution still showed radioactivity. They established that...