Courtois, Bernard (1777-1838) was a French chemist who discovered the element iodine in 1811.

Courtois was born on Feb. 8, 1777, in Dijon, France. His father was a manufacturer of saltpeter, a nitrate compound used in making matches, gunpowder, explosives, and fertilizers. As a young boy, Courtois worked in his father's plant and demonstrated a keen interest in chemistry.

Courtois apprenticed a pharmacist and later studied pharmacy at the Ecole Polytechnique. He then served in the French army as a pharmacist. During this time, he isolated pure morphine from opium. He was the first ever to accomplish this feat.

Meanwhile, the Courtois family business was hitting hard times, because India could produce and sell saltpeter more cheaply. Courtois returned to help his father, who obtained saltpeter from seaweed ashes by leaching the ash with water and then evaporating the liquid to obtain the sodium and potassium salts. During the process, a strong acid was added to remove undesirable compounds. In 1811, while extracting the salts, Courtois added too much sulfuric acid to the seaweed ash. To his surprise, violet vapors became visible and condensed to form dark crystals. Believing this was a new element, Courtois prepared numerous compounds of it and researched its properties. His work was announced in 1813. Later that year, the substance was verified as an element by British chemist Humphry Davy and French chemist Joseph Louis Gay-Lussac and named iodine. The name iodine comes from the Greek word for “violet.” Iodine's chemical symbol is I.

After the Napoleonic Wars, the Courtois saltpeter business failed. Although Courtois started an iodine manufacturing business, it too failed, and he died a poor man.