Iodization of Salt in 1924 Increased American IQs 15 Points

Iodine deficiency is the leading cause of preventable mental retardation in the world today. The condition, which was common in the developed world until the introduction of iodized salt in the 1920s, is connected to low iodine levels in the soil and water. We examine the impact of salt iodization on cognitive outcomes in the US by taking advantage of this natural geographic variation. Salt was iodized over a very short period of time beginning in 1924. We use military data collected during W...

 Davy VS Gay-Lussac in the Race to Discover Iodine

He was warmly received by Cuvier, Ampère and Berthollet, but got into an awkward priority dispute with the gifted young chemist Joseph Gay-Lussac. Gay-Lussac, Davy’s exact contemporary, had made a popular name in France with his intrepid ballooning exploits, and had been hard on Davy’s heels with potassium and sodium experiments. Both were now given by the Académie des Sciences a newly isolated substance to analyse: a strange violet crystal recently found as a byproduct of gunpowder man...