In a now controversially reviewed process, it was stated that emanium is identical to actinium, which was discovered by André-Louis Debierne in 1899.

Shortly after publication of the discovery of polonium in the summer of 1898, he started to isolate the new element from the waste of uranium production in the chemical plant E. de Haën in Hanover.

[3] The use of Sidot's blende (zinc sulfide) instead of barium platinocyanide as a luminescence material to make the radioactive rays visible was a commonly accepted improvement.

[3][4] Because of prolonged contact with radioactive material, fingers of his right hand had to be amputated and he suffered from lung cancer.

Debierne, who is now considered by the vast majority of historians as the discoverer, lost interest in the element and left the topic.

Giesel, on the other hand, can rightfully be credited with the first preparation of radiochemically pure actinium and with the identification of its atomic number 89.