Soddy, Frederick – The origin of the entirely new concept of isotopes
Type of Spiritual Experience
A description of the experience
Frederick Soddy: The Scientist as Prophet – Professor Mansel Davies [May 1991]
His next major enlightenment is given by a quotation from the Annual Reports of the Chemical Society for 1910 where he wrote:
The recognition that elements of different atomic weight may possess identical properties [but had been found, in instances, to differ completely in radioactivity: M.D.] seems destined to have its most important application in the region of the inactive elements.
This statement not only shows the origin of the entirely new concept of isotopes, but also illustrates very directly the extraordinary intuitive insight which Soddy brought to his studies.
On the further basis of work done in the Glasgow laboratories by Fleck under his guidance, Soddy published in February 1913 his complete and correct version of the Periodic Table displacements associated with radioactive changes. It is significant that while Fajans quite independently came to the same findings, Fajans was so far from appreciating the character of the changes involved, that he interpreted his results as evidence against the nuclear origin of those changes.
It was in a communication to Nature (December 4, 1913) that Soddy announced the term 'isotope'.