In his presidential address to the chemistry section of the British Association in 1907, Arthur Smithells pointed to work in radioactivity with wonder, calling it the ‘chemistry of phantoms’. Indeed, the transitory nature of the radioelements, coupled with the exceedingly small quantities commonly handled, made many a traditional chemist hesitant to accept these unusual substances as real elements worthy of insertion into the periodic table. Besides, there were too many of them: by 1913 over thirty radioelements were known, but there were no more than twelve boxes in the periodic table in which to house them. Moreover, there was much confusion about radioelements that had different physical properties such as half-life and range of emitted alpha particle, but which could not be separated chemically. Small wonder then that Alexander Russell, the only person who worked with both Ernest Rutherford and Frederick Soddy, recalled the prevalent attitude of chemists as discouraging of interpretative attempts: theirs was, so they claimed, ‘an experimental science. No good ever came from pontificating on the ways of Nature from the comfort of an armchair. The laboratory bench, not the sofa, … was where the truth would be found’.