"The Black Camel" is probably my favorite Charlie Chan novel and the film version is my favorite Chan movie. The picture follows the book quite closely, as you mentioned.
Diana Dixon appears but very briefly in the movie as "Miss Dixon," an uncredited part. The butler role in the film, Jessop, is quite different from that in the book!
I feel that the book is a good "companion" to the movie, as it does add another dimension, mainly one of details that, as you mention, cannot be included in a 71-minute film. To me, it's fun to let the two versions of this story blend with one another.
Yes, "The Black Camel" is, as you say, a worthwhile read! Hopefully, more fans of Charlie Chan will treat themselves to the fine original stories by Earl Derr Biggers that inspired the movie versions.
To be honest I have never liked the Biggers stories as much as the films, but I reread CAMEL a couple of months ago. It definitely fleshes out some of the characters as featured in the movie and adds to the overall enjoyment of the story.
It is impossible for me to read these stories without having a mental picture of Warner Oland as Chan which is ironic considering that Toler was the one who tried to model his Chan after the novels.
I, too, picture Warner Oland in the role of Charlie chan when I read the Biggers novels. It makes sense, actually, I feel, as Biggers, himself, was as pleased as could be with Oland's personification. Also, except for "Keeper of the Keys," all of the stories were originally made into Oland Chan films. (The "proto-Chan" silent movies as well as the talking "Behind That Curtain" were, in my opinion, Charlie Chan pictures in little more than name. Biggers' stories were changed drastically, especially in the silents, and Chan was little more than an afterthought.)
