Saccharin - discovered by a guy who forgot to wash his hands - the Awesome World of Things
Ira Remsen and Constantin Fahlberg paused to eat at work in a laboratory at Johns Hopkins University. Fahlberg never washed his hands and noticed an oddly sweet flavour during his meal. Artificial sweetener as born as Fahlberg related to taste to the compound they had been working on in the lab. Although both published their findings it was Fahlberg who patented it. It became popular during sugar shortages during the world wars and later with dieters as a means of losing weight.
Read more about saccharin on LinkedIn here.