to a wisdom tooth extraction by Dr. John Riggs. Wells discovered that he was unaware of the procedure and experienced absolutely no pain during the procedure. In 1824, Henry Hill Hickman used carbon dioxide to achieve a state of "suspended animation" in animals; successfully diminishing pain during the surgical procedure. In 1831, chloroform was discovered by Justus von Liebig in Germany, Samuel Guthrie in New York and Eugène Soubeiran in France, all of whom worked independently. In 1842, a chemist in Rochester, William Edward Clarke provided Dr. Elijah Pope with ether prior to a tooth extraction of his patient. In the same year, a doctor in Georgia, Dr. Crawford W. Long administered ether to John Venable for the removal of a neck tumour. References Anesthesia