Mezzotinting
This art was suggested by the simple accident of the gun-barrel of a sentry becoming rusted with dew.
Whitening Sugar
The process of whitening sugar was discovered in a curious way. A hen that had gone through a clay puddle went with her muddy feet into a sugar house, leaving her tracks on a pile of sugar. It was noticed that wherever her tracks were the sugar was whitened. Experiments were instituted, and the result was that wet clay came to be used in refining sugar.