Four popular artificial sweeteners were discovered when scatter-brained scientists tasted them by accident, according to an article on the news and humor site Cracked.com. Sucralose, aspartame, saccharin and cyclamate all came into being when scientists stumbled upon sweet-tasting substances while working in labs.
Sucralose, the sweetener marketed under the brand name Splenda, was discovered when a foreign grad student misread classroom instructions. He read "testing" as "tasting," and when he obligingly sampled the chemical he was working with, he discovered it had a sweet flavor.
Scientist Jim Schlatter stumbled upon aspartame (the main ingredient in NutraSweet and Equal) when he licked his finger to turn the page of a text he was reading. He realized the sweetness he was tasting was due to the chemical he'd just been experimenting on.
Grad student Constantine Fahlberg didn't wash his hands after working in the lab. When he ate dinner later that night, he noticed the bread was very sweet. He then licked his hands and clothes, and even returned to the lab to taste the chemicals he'd used earlier on. The flavor he'd tasted was saccharin.
Cyclamate, found in Canadian Sweet n' Low, was discovered through a double laboratory no-no: a scientist was smoking while performing chemical experiments. He put his cigarette down on the table, and when he picked it back up again, it had a sweet taste.
There you have it: without scientists' negligence, we wouldn't have diet soda.