Kitab-i-Iqan — Paragraph 166

Be that as it may, the real elixir will, in one instant, cause the substance of copper to attain the state of gold, and will traverse the seventy-year stages in a single moment. Could this gold be called copper? Could it be claimed that it hath not attained the state of gold, whilst the touch-stone is at hand to assay it and distinguish it from copper?