Orsted's 1825 method was not fully published or independently repeated at the time, while Wohler's 1827 work is the first isolation historians can verify in detail; whether "first isolation" should credit priority in time or the first confirmable result is a genuine, unresolved editorial question, not a missing fact.
What would resolve this A surviving, dated laboratory record of Orsted's exact 1825 method and result, sufficient for modern chemists to confirm what he actually produced, would settle whether his claim meets the same evidentiary bar Wohler's does.
OpenHistory of chemistryWikipedia contributors, Aluminium (Wikipedia)