11 Scientific Discoveries That Were Total Accidents

To be fair, the British pharmacist who accidentally invented the friction match was actually trying to invent matches. But crucially, John Walker was attempting to create a much more dangerous and volatile chemical match when he made his discovery.

In the past, if you wanted to set something on fire, you would have to transfer it from a big fire in a hearth  to a taper or candle. The first self-igniting match worked by dipping a stick coated with potassium chlorate, sulphur, sugar, and rubber into a small asbestos bottle filled with sulphuric acid.

None of which, you'll probably agree, sounds particularly safe.

Walker was trying to create one of these kinds of matches when he accidentally scraped the stick he was using to stir the chemicals against the hearth. It spontaneously combusted and, voila, he had invented the safety match. These were much easier to use and much less likely to burst into flames in your pocket or explode in your face.

Walker chose not to patent his invention as he nobly believed that it was for the benefit of all mankind. 

The rest of the world responded significantly less nobly and promptly ripped off his design to make a shed load of money.