Perey thought this decay activity might have been caused by a previously unidentified decay product, one that was separated during purification, but emerged again out of the pure actinium-227.
pˈɛɹi θˈɔːt ðɪs dᵻkˈeɪ æktˈɪvᵻɾi mˌaɪthɐv bˌɪn kˈɔːzd baɪ ɐ pɹˈiːviəsli ˌʌnaɪdˈɛntᵻfˌaɪd dᵻkˈeɪ pɹˈɑːdʌkt, wˈʌn ðæt wʌz sˈɛpɚɹˌeɪɾᵻd dˈʊɹɹɪŋ pjˌʊɹɹɪfɪkˈeɪʃən, bˌʌt ɪmˈɜːdʒd ɐɡˈɛn ˌaʊɾəv ðə pjˈʊɹ æktˈɪniəm tˈuːhˈʌndɹɪd twˈɛnti sˈɛvən.