Sherlock Holmes primarily relies on abduction: inferring an explanation for observed details. "From a drop of water", he writes, "a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other". In "A Scandal in Bohemia", Holmes infers that Watson had got wet lately and had "a most clumsy and careless servant girl". When Watson asks how Holmes knows this, the detective answers: In the first Holmes story, "A Study in Scarlet", Dr. Watson compares Holmes to C. Auguste Dupin, Edgar Allan Poe's fictional detective, who employed a similar methodology. Alluding to
André Marie Jean Jacques Dupin "Principia Juris Civilis", 5 vols. (1806); "Mémoires et plaidoyers de 1800 au 1ier janvier 1830", in 20 vols.; and "Mémoires ou souvenirs du barreau", in 4 vols. (1855–1857). His brother, Pierre Charles François Dupin, was a mathematician. André Marie Jean Jacques Dupin André Marie Jean Jacques Dupin (1 February 17838 November 1865), commonly called Dupin the Elder, was a French advocate, president of the chamber of deputies and of the Legislative Assembly. Dupin was born at Varzy, in the Nièvre "département", in France. He was educated by his father, who was a lawyer of eminence, and at an early age