Antedating of "break a leg" (1940)

[Sam Clements]

Got lucky and found a Google Books hit for this in 1940, which predates a 1948 cite. And, the 1940 edition was in a local college library which I visited this evening.  Photocopied the page.  

The Theatre Handbook; And Digest of Plays by Bernard Sobel, Published by Crown, 1940.  page 722,
  
 "Before a perfomance actors never wish each other good luck, but say "I hope you break a leg";

This doesn't disprove the German "Hals und Beinbruch" as a possible source predating my 1940.

Sam Clements

------------------------------------------------------------
The American Dialect Society - http://www.americandialect.org