Parke-Davis Blue Book: A Reference Catalog of Selected Scientific Preparations for Physicians ($10, which is 1/3 the internet price.)
Included here are the drugs produced by Parke-Davis in 1938: endocrine preps (and sex hormones), pharmaceutical specialties, vitamins, and biological preps (vaccines).
Some of these drugs we still use today, like adrenalin, digitalis, sulfanimide, and the TB PPD test.
Sometimes the methods of administration are different from now- the use of a glass "Vaporizer" (nebulizer) to give "oral inhalation treatments."
Sometimes the indications for use turn your stomach- theelin suppositories to treat gonorrheal vaginitis in children, arsenic injections for syphilis, tar ointment for eczema, mercury as a disinfectant.
I liked the diagrams and photos. Look for this book on the new non-fiction table, avail. 1/11. (Later: the med. section)