There were at least four erroneous and incomplete discoveries before Marguerite Perey of the Curie Institute in Paris, France discovered francium in 1939 by purifying a sample of actinium-227, which had been reported to have a decay energy of 220 keV.
ðɛɹwˌɜːɹ æt lˈiːst fˈoːɹ ɛɹˈoʊniəs ænd ɪŋkəmplˈiːt dɪskˈʌvɚɹiz bᵻfˌoːɹ mˌɑːɹɡɚɹˈiːt pˈɛɹi ʌvðə kjˈʊɹɹi ˈɪnstɪtˌuːt ɪn pˈæɹɪs, fɹˈæns dɪskˈʌvɚd fɹˈænsiəm ɪn nˈaɪntiːnhˈʌndɹɪd θˈɜːɾi nˈaɪn baɪ pjˈʊɹɹᵻfˌaɪɪŋ ɐ sˈæmpəl ʌv æktˈɪniəm tˈuːhˈʌndɹɪd twˈɛnti sˈɛvən, wˌɪtʃ hɐdbɪn ɹᵻpˈoːɹɾᵻd tə hæv ɐ dᵻkˈeɪ ˈɛnɚdʒi ʌv tˈuːhˈʌndɹɪd twˈɛnti kˈiː vˈiː.