Alchemy

The science by aid of which the chemical philosophers of medieval times attempted to transmute the baser metals into gold or silver. There is considerable divergence of opinion as to the etymology of the word, but it would seem to be derived from the Arabic al=the, and kimya=chemistry, which in turn derives from the late Greek chemica=chemistry, from chumeia=a mingling, or cheein, 'to pour out' or 'mix', Aryan root ghu, to …

…will be no result, but if a touch of some acid be added, it will oxidize. The explanation is that "the acid provokes oxidation of the metal because it has an affinity for the oxide which tends to form." - a material fact most metaphysical in its production, and only explicable thereby. He concluded his argument with an appeal for tolerance towards the medieval alchemists, whose work is underrated because it is not properly understood.