Saltire detected the symbol, which often appears with balls in the quadrants formed by the arms of the chi-cross, in standards that appear on the coins of Persepolis. She suggested that early Christians endorsed its solar symbolism as appropriate to Christ. She also wrote: "although it cannot be proved, ... in the white saltire of St. Andrew we still have a reminiscence of the old standard of the Persepolitan kingdom". In the old European Union standard, a black saltire set in an orange square is the hazard symbol for irritants (Xi) or harmful chemicals (Xn). It indicates a hazard less severe
Caduceus as a symbol of medicine intended to be a symbol of medicine. The inconsistency was noticed several years later by the librarian to the Surgeon General, but for reasons which are not entirely clear, the symbol was not changed. Considerable light is shed on this confusion by an anonymous letter republished by Emerson, a historian of United States Army insignia and uniforms. He indicates that the April 1924 issue of "The Military Surgeon" printed a review of an earlier article that appeared in the "Presse Medicale" in which the author stated "There is nothing in history to justify the use of the caduceus as the