After being out of circulation for many years, partly because of the 1959 Hammer remake (The Hound of the Baskervilles (1959)) in Technicolor starring Peter Cushing, this film was restored and re-released to theaters in 1975 with great fanfare, to the point of having the national evening news do a story on it. The film was shown at its full 80-minute length, and newspaper and magazine articles commented on the fact that the line "Oh, Watson, the needle!", referring to Holmes' cocaine habit (and usually misquoted as "Quick, Watson, the needle!") was put back in after having been cut by the censors. As an added attraction, the studio added a rare sound film featurette which showed Sir Arthur Conan Doyle, author of the Sherlock Holmes books, talking about his creation.
This was such a hit that Basil Rathbone and Nigel Bruce were hired to play Holmes and Watson on the radio series "The New Adventures of Sherlock Holmes." This radio series consisted of new Sherlock Holmes stories written by Anthony Boucher and Denis Green.
While not entirely passive, Watson's original role was mostly as an observer of Holmes and the chronicler of his cases. With this film a new tradition began where Watson enjoyed equal billing with Holmes. In Nigel Bruce's hands the character became a comedic foil and a bit of a bumbler. Later interpretations would vary, but the character remained greater than literature's original enigma.
Watson's revolver in this film is easily identifiable as a Colt Single Action Army, aka the Peacemaker, widely identified with the American "Wild West." However, over 5300 of these were sold in England through Colt's Pall Mall agent between 1874 and 1912, and were chambered in nearly every caliber approved by the British Army. Since officers (like Watson) purchased their own sidearms, this is, somewhat counter-intuitively, one of the more realistic choices made by a film maker of what Watson's service revolver might have actually been.
In the original novel, and in all later film versions, the butler is named Barrymore. In the 1939 version, this had to be changed to Barryman because the famous Barrymore family was still acting in films.
The original title "The Hound of the Baskervilles" refers to a dog that terrorizes a family called "Baskerville". The German title "Der Hund Von Baskerville", a mistranslation, refers to a hound, which just lives in "Baskerville", a town, that does not play a role in the story.