Beginning of Essay
Science , ancient art practiced especially in the Middle Ages, devoted chiefly to discovering a substance that would transmute the more common metals into gold or silver and to finding a means of indefinitely prolonging human life. Although its purposes and techn ....

Middle of Essay
.... and silver to be burned in order to stop such experiments. Zosimus the Theban (about AD 250-300) discovered that sulfuric acid is a solvent of metals, and he liberated oxygen from the red oxide of mercury. The fundamental concept of stemmed from the Aristotelian doctrine that all things tend to reach perfection. Because other metals were thought to be less "perfect" than gold, it was reasonable to assume that nature formed gold out of other metals deep within the earth and that with sufficient skill and diligence an artisan could duplicate this process in the workshop. Efforts toward this goal were empirical and practical at first, but by the 4th ....