Apparatus used in an experiment to monitor the decay of radium, 1904.
© Science Museum / Science & Society Picture Library
Diagram of apparatus used to detect the production of helium from radium, taken from 'Radio-Activity: An Elementary Treatise, from the standpoint of the disintegration theory', by Frederick Soddy MA (1877-1956), lecturer on physical chemistry and radioactivity at the University of Glasgow. Soddy conducted chemical research into radiactive materials, collaborating with Ernest Rutherford amongst others, and determined that radioactive materials underwent a proces of atomic disentegration leading to the formation of new, more stable atoms of other elements. He discovered that the radioactive decay of a sample of radium bromide produced atoms of helium. Soddy's work earned him the Nobel Prize for Chemistry in 1921.