The brown iodine we buy in drugstores is not pure iodine. It is iodine dissolved in alcohol. Pure iodine is a solid. It forms small, dark crystals. These crystals turn to a beautiful purple vapor when they are heated.
Our bodies have to have iodine. Goiter is a disease that is sometimes caused by not getting all we need. People who live near the seacoast seldom have goiter. They get enough iodine from fish and other sea food. People who live far from the sea often use iodized salt to make sure that they get enough iodine. Iodized salt is salt to which iodine has been added.
Much iodine is used in medicine. Chemists use a great deal, too.
Iodine is one of the simple substances called elements. It is never found pure in nature. It can be obtained from seaweed or from minerals found in the ground.
The people of ancient times did not know iodine. A French scientist first discovered it in 1811. He was trying to make gunpowder for Napoleon. He thought that he might be able to get one of the necessary materials from seaweed. In the seaweed he found iodine.
