Prior to The Hound of the Baskervilles, March of 1939, Basil Rathbone was considered the Arch-Master of the Sinister, and he was probably difficult to accept as Holmes, as seen in the following prize winning letter in the November, 1939, edition of Modern Screen.
Really the story of The Adventures of Sherlock Holmes, did not begin with its premier on September 1, 1939 but started with the research, rehearsals and training for The Hound of the Baskervilles. It was there and then that Basil Rathbone honed his skills, adapting his already brilliant acumen for the camera in countless parts of villainy, to the intense, sharp-tongued, witty and well spoken Holmes. And regardless if some had difficulties accepting Rathbone and his portraying the heroic sleuth of Conan Doyle fame, because of previous villainous stardom, or simply that Rathbone would have to survive the comparison not only of those actors who had traversed the Sherlockian way, but also be evaluated against the literary Holmes, it was enough to stop anyone from accepting the part; but it was clear from the get-go, that Rathbone fit Holmes to a T., or like a glove.
In preparation for the role of Sherlock Holmes (Hound of the Baskervilles), Rathbone was taught to play the violin; a member of the 20th Century-Fox, musical department was assigned the task of teaching Rathbone to play, just not too well.
It was announced in April of 1939 that a second Holmes picture would be produced, but Rathbone refused to sign a contract for a series; Rathbone feared he might not be able to escape the character of Holmes. And today, of course he is best known and most fondly remembered for his on screen rendition of the master detective. The Adventures of Sherlock Holmes began production in late spring of 1939, soon after the box-office success of its predecessor, The Hound of the Baskervilles. The opening date at this point seemed unsettled, the initial publicity said September 1, and then it was projected as a 1939-1940 release. Adventures was based on the play by noted actor playwright, William Gillette; although the movie resembles little of Gillette’s work.
Sidney Lanfield, director of The Hound of the Baskervilles, was set to direct Adventures of Sherlock Holmes, but for some unknown reason (ah, the caprice of producers) in June of 1939, Alfred L. Werker was chosen to take the helm for the second Holmes installment.
The cast, from top to bottom was superb (what would Holmes be without Watson, so to, what would Rathbone have been as Holmes without Nigel Bruce as Watson?), the crew did exactly what was expected of them and more; and now this film along with several others of the Basil Rathbone and Nigel Bruce, Holmes movies are a permanent part of the lore of Sherlock Holmes. Other actors have done fine by Holmes, but none have looked the part as well as Rathbone, who uncannily resembled the drawings so famously associated with the original publication of the stories and matched so closely the descriptions laid down by Doyle himself.
The Adventures of Sherlock is available on DVD at TCM.com.
By C. S. Williams
 Harrisburg Telegraph (Harrisburg, Pennsylvania) January 26, 1939
 Fitchburg sentinel (Fitchburg, Massachusetts) April 26, 1939
 Variety, June 21, 1939
 Film Daily, May 15, 1939
Variety, July 12, 1939
 Film Daily, April 18, 1939
 Film Daily, June 5, 1939