Moissan isolating fluorine. Historical artwork of the French chemist Henri Moissan (1852-1907) as he isolates fluorine in 1886. The electrolysis set-up at right centres on a beaker containing a U-tube in a cooling liquid (at -23 degrees Celsius). The U-tube contains a solution of potassium fluoride (provides electrical conductivity) in hydrofluoric acid. The electrical wires connect to electrodes (iridium/platinum) dipped inside the U-tube. Side tubes allow collection of the products (hydrogen gas, right; fluorine gas [yellow], left). Moissan was awarded the 1906 Nobel Prize for Chemistry for his work on fluorine and electric arc furnaces. From Physique Populaire (E. Desbeaux, 1891).