Perey thought this decay activity might have been caused by a previously unidentified decay product, one which was separated during purification, but emerged again out of the pure actinium-227.
Perey mengira aktivitas peluruhan ini mungkin disebabkan oleh produk peluruhan yang tidak teridentifikasi sebelumnya, yang terpisah saat pemurnian, tapi muncul kembali dari aktinium-227 murni.