In 1879, chemist Constantin Fahlberg made a sweet mistake at dinner—his bread tasted sugary, but the sweetness was coming from his fingers. He’d unknowingly carried lab chemicals from coal tar back to the table.

Instead of washing up, Fahlberg raced back to the lab and pinpointed the compound: saccharin, the world’s first artificial sweetener. He patented it, and it took off—especially during WWI sugar shortages and later with diabetics and dieters.

Though it faced controversy in the 1970s over cancer concerns, later research cleared it, and saccharin is still sweetening foods today.