A cartoon in a recent issue of the New Yorker depicts an old man on his deathbed. Standing beside him, the doctor transmits whispered last words to the surrounding kin, "He says he has one last request. Will someone please look up the word 'serendipity' and tell him what it means." Whatever the intended barb, it strikes a sympathetic chord. Ever since the word was introduced more than two centuries ago, scientists have been trying to tell what it means.
When Horace Walpole coined "serendipity" in a letter to Horace Mann, he refrained from defining it. "You will understand it better," he wrote, "by the derivation than by the definition." Then he proceeded to relate an old fairy tale, "The Three Princes of Serendip," who, as they traveled abroad, made discoveries "by accidents and sagacity of things which they were not in quest of." This "derivation" has since become the