Referring to himself as a "consulting detective" in his stories, Holmes is known for his proficiency with observation, deduction, forensic science and logical reasoning that borders on the fantastic, which he employs when investigating cases for a wide variety of clients, including Scotland Yard.

[7] The character and stories have had a profound and lasting effect on mystery writing and popular culture as a whole, with the original tales, as well as thousands written by authors other than Conan Doyle, being adapted into stage and radio plays, television, films, video games, and other media for over one hundred years.

In this 1871 novel (sixteen years before the first appearance of Sherlock Holmes), Henry Cauvain imagined a depressed, anti-social, opium-smoking polymath detective, operating in Paris.

[45] Legend has it that Londoners were so distraught upon hearing the news of Holmes's death that they wore black armbands in mourning, though there is no known contemporaneous source for this; the earliest known reference to such events comes from 1949.

[100] In The Hound of the Baskervilles, the detective recognises works by Godfrey Kneller and Joshua Reynolds: "Watson won't allow that I know anything of art, but that is mere jealousy since our views upon the subject differ.

"[101] In "The Adventure of the Bruce-Partington Plans", Watson says that "Holmes lost himself in a monograph which he had undertaken upon the Polyphonic Motets of Lassus", considered "the last word" on the subject—which must have been the result of an intensive and very specialized musicological study which could have had no possible application to the solution of criminal mysteries.

[102][103] Holmes is a cryptanalyst, telling Watson that "I am fairly familiar with all forms of secret writing, and am myself the author of a trifling monograph upon the subject, in which I analyse one hundred and sixty separate ciphers.

"[104] Holmes also demonstrates a knowledge of psychology in "A Scandal in Bohemia", luring Irene Adler into betraying where she hid a photograph based on the premise that a woman will rush to save her most valued possession from a fire.

[107] Holmes observes the dress and attitude of his clients and suspects, noting skin marks (such as tattoos), contamination (such as ink stains or clay on boots), emotional state, and physical condition in order to deduce their origins and recent history.

When Watson asks how Holmes knows this, the detective answers: It is simplicity itself ... my eyes tell me that on the inside of your left shoe, just where the firelight strikes it, the leather is scored by six almost parallel cuts.

[129] Ballistics feature in "The Adventure of the Empty House" when spent bullets are recovered to be matched with a suspected murder weapon, a practice which became regular police procedure only some fifteen years after the story was published.

"[133] Guy Mankowski has said of Holmes that his ability to change his appearance to blend into any situation "helped him personify the idea of the English eccentric chameleon, in a way that prefigured the likes of David Bowie".

[1] The character was so well known that in 1893 when Arthur Conan Doyle killed Holmes in the short story "The Final Problem", the strongly negative response from readers was unlike any previous public reaction to a fictional event.

Other conventions introduced by Doyle include the arch-criminal who is too clever for the official police to defeat, like Holmes's adversary Professor Moriarty, and the use of forensic science to solve cases.

After the festival, items were transferred to The Sherlock Holmes (a London pub) and the Conan Doyle collection housed in Lucens, Switzerland, by the author's son, Adrian.

Susan Cannon Harris claims that themes of contagion and containment are common in the Holmes series, including the metaphors of Eastern foreigners as the root cause of "infection" within and around Europe.

[197] Lauren Raheja, writing in the Marxist journal Nature, Society, and Thought, claims that Doyle used these characteristics to paint eastern colonies in a negative light, through their continually being the source of threats.

For example, in one story, Doyle makes mention of the Sumatran cannibals (also known as Batak) who throw poisonous darts, and in "The Speckled Band", a "long residence in the tropics" was a negative influence on one antagonist's bad temper.

[198] Yumna Siddiqi argues that Doyle depicted returned colonials as "marginal, physically ravaged characters that threaten the peace", while putting non-colonials in a much more positive light.

[199] The popularity of Sherlock Holmes has meant that many writers other than Arthur Conan Doyle have created tales of the detective in a wide variety of different media, with varying degrees of fidelity to the original characters, stories, and setting.

An especially influential pastiche was Nicholas Meyer's The Seven-Per-Cent Solution, a 1974 New York Times bestselling novel (made into the 1976 film of the same name) in which Holmes's cocaine addiction has progressed to the point of endangering his career.

It served to popularize the trend of incorporating clearly identified and contemporaneous historical figures (such as Oscar Wilde, Aleister Crowley, Sigmund Freud, or Jack the Ripper) into Holmesian pastiches, something Conan Doyle himself never did.

[207] In terms of writers other than Conan Doyle, authors as diverse as Agatha Christie, Anthony Burgess, Neil Gaiman, Dorothy B. Hughes, Stephen King, Tanith Lee, A.

[216] The Final Solution, a 2004 novella by Michael Chabon, concerns an unnamed but long-retired detective interested in beekeeping who tackles the case of a missing parrot belonging to a Jewish refugee boy.

[217] Mitch Cullin's novel A Slight Trick of the Mind (2005) takes place two years after the end of the Second World War and explores an old and frail Sherlock Holmes (now 93) as he comes to terms with a life spent in emotionless logic;[218] this was also adapted into a film, 2015's Mr.

[200][226] Many others soon followed, with the protagonists often given thinly veiled names such as Sherlaw Kombs (by Robert Barr),[227] Picklock Holes (by R. C. Lehmann), Shamrock Jolnes (by O. Henry), Holmlock Shears, Shylock Homes, and so on.

[207] In 1944, American mystery writers Frederic Dannay and Manfred B. Lee (writing under their joint pseudonym Ellery Queen) published The Misadventures of Sherlock Holmes, a collection of thirty-three pastiches written by various well-known authors, featuring numerous parodies.

[231][232] In 2012, Guinness World Records listed Holmes as the most portrayed literary human character in film and television history, with more than 75 actors playing the part in over 250 productions.

In the series, created by Mark Gatiss and Steven Moffat, the stories' original Victorian setting is replaced by present-day London, with Watson a veteran of the modern War in Afghanistan.

[259][260] In the United Kingdom, it was revived in 1996 due to new provisions harmonising UK law with that of the European Union, and expired again at the end of 2000 (seventy years after Conan Doyle's death).