Early Chinese medical writings in approximately 3600 B.C. were the first to record the decreases in goiter size upon ingestion of seaweed and burnt sea sponge. Although iodine was yet to be discovered, these remedies remained effective and their use continued globally, as was documented in writings by Hippocrates, Galen, Roger, and Arnold of Villanova in later centuries. The discovery of iodine was made incidentally during the early part of the 19th century.
In 1811, while extracting sodium salts necessary for the manufacture of gunpowder, Bernard Courtois, a French chemist, observed an unusual purple vapor arising from seaweed ash treated with sulphuric acid. Studies of this previously unrecognized substance were continued by Joseph Louis Gay-Lussac, Andre Anpere, Sir Humphry Davy, and others. In 1813, the first paper presenting the new element, iodine (termed after the Greek word, …
