The discovery of aspirin is often cited as an example of serendipity. At the end of the 19th century a German chemist was attempting to find a cure for rheumatism when he produced aspirin. It was then found to be an extremely effective pain killer. Thus the chemist had discovered aspirin by chance.
Serendipity is the fact of finding pleasant or useful things by chance. The word derives from a short story by the British writer Horace Walpole (1717 – 1797) who wrote a story called 'The Three Princes of Serendip' in which the heroes of the story made a number of discoveries by complete chance or happy accident. It is believed that Walpole took the name Serendip from an old name for the island of Sri Lanka.
Other serendipitous discoveries include cellophane, the sweetener aspartame, penicillin, Teflon and gelignite.