Saccharin

Saccharin is a non-nutritive artificial sweetener, a sultam compound that appears as odorless white crystals, about 500 times sweeter than sucrose though carrying a bitter or metallic aftertaste at high concentrations. It is used to sweeten beverages, candies, baked goods and tobacco products and to mask the bitter taste of medicines. The chemist Constantin Fahlberg first produced it in 1879 at Johns Hopkins University while studying coal tar derivatives, discovering its sweetness after noticing a sweet taste on his hand one evening and tracing it to the benzoic sulfimide he had been working with that day; it saw little use until sugar shortages during the First World War, and it became popular again with dieters in the 1960s and 1970s as a calorie free sweetener.