 —require greater expertise, and types and quantities of chemicals and equipment that are more difficult to source, and so are more rarely used, illicitly (but cases have been recorded).An opium-based elixir has been ascribed to alchemists of Byzantine times, but the specific formula was lost during the Ottoman conquest of Constantinople (Istanbul).Around 1522, Paracelsus made reference to an opium-based elixir that he called "laudanum" from the Latin word "laudare", meaning "to praise" He described it as a potent painkiller, but recommended that it be used sparingly.