Books on the ricardo’s Bedroom Shelf: On Your Guard ! by Warren

On your guard ! The prevention and treatment of sex dis-
eases, by Carl Warren, advised and assisted by eminent specializing physicians ;
foreword by M. J. Exner . . .
frontispiece and illustrations by C. D. Batchelor. New York, Emerson books, inc., 1937 Pre war study of Venerial diseases and Contraception.  Bookseller Inventory # 003004

This pre-war book was written before the widespread use of Penicillin which occurred during WW2.
See it at Amazon

http://www.abebooks.com/Guard-Carl-Warren-1937-Emerson-New/1072889458/bd

http://www.alibris.com/search/books/author/Warren-Carl/title/On-Your-Guard-the-Prevention
ref:
http://journals.lww.com/ajnonline/Citation/1937/08000/ON_YOUR_GUARD___THE_PREVENTION_AND_TREATMENT_OF.41.aspx