The complete Sherlock Holmes - Google Books
Lestrade is speaking, and context makes it clear that Conan Doyle was not using an Americanism.
Yes, it is clear from the context, thanks Ang. But if Doyle had used it in the way we do, it wouldn't have been an Americanism.
Well, when British writers use phrases we now consider Americanisms, often they are simply archaic forms, e.g. "I guess," as seen in Chaucer every page or two. But if you mean to call me inflexible, that is erroneous..