There are other examples besides lead cups. Most nutritional deficiencies have only recently been recognized; scurvy’s solution was famously lost for a century, and while there were folk remedies even back in the Roman era for curing goiters with seaweed, none of them indicate any understanding of the subtler effects on intelligence.
There are other examples besides lead cups. Most nutritional deficiencies have only recently been recognized; scurvy’s solution was famously lost for a century, and while there were folk remedies even back in the Roman era for curing goiters with seaweed, none of them indicate any understanding of the subtler effects on intelligence.