« This discovery indeed is almost of that kind which I call Serendipity, a very expressive word, which as I have nothing better to tell you, I shall endeavor to explain to you : you will understand it better by the derivation than by the definition. I once read a silly fairy tale, called « The Three Princes of Serendip » : as their highnesses travelled, they were always making discoveries, by accidents and sagacity, of things they were not in quest of… »