An example of a historical idea now considered an alternative conception.
"In his Coleum Philosophorum Paracelsus wrote that by the mediation of fire any metal could be generated from mercury. He considered mercury an imperfect metal; it was wanting in coagulation, which was the end of all metals. Up to the half-way point of their generation all metals were liquid mercury, he believed, and gold was simply mercury which had lost its mercurial nature by coagulation. Hence if he could but coagulate mercury sufficiently, he could make gold And while he tried hundreds of different methods to bring this about, in the end he admitted failure. 'From the seed of an onion, an onion springs up, not a rose, a nut, or a lettuce', he declared."
Bernard Jaffe (1934) Crucibles. The Lives and Achievements of the Great Chemists. Jarrolds Publishers.
This is an alchemical idea of transmutation.
