Substances that contain iodine, praised in antiquity. For 3 thousand years before it became known this item, people already knew that for goiter need to use seaweed, which contains a lot of iodine.
Opened this item quite by chance in 1811 the French scientist Bernard Courtois acted on the ashes of seaweed with sulfuric acid. And when, as they say, it poured over the vessel suddenly appeared purple pair, which when cooled settled in the form of black crystals with a metallic sheen. Iodine in Greek means "purple"
There is another version of the opening of iodine. According to her, the hero of the opening was a favorite cat Courtois: he was lying on the shoulder of the chemist, when he worked in the laboratory. Wanting to have fun, the cat jumped on the table and pushed on the floor standing near the vessels. One of them was alcohol solution of the ash of seaweed, and the second sulfuric acid. After mixing liquids appeared a cloud of blue-violet pair, which was nothing more than the iodine.
Only in 1813, Joseph Louis Gay-Lussac studied this item and gave it its present name.