"identified as Madame Olga’s Dream Book"

Interest in the meaning of dreams was inspired by the publication in 1899 of Sigmund Freud's book on the interpretation of dreams (Die Traumdeutung) and by the work of Carl Jung. By the 1930s Freud's ideas had become widely known, and this is reflected in the fact that when Flora visits Meriam after her confinement, she is reading Madame Olga's Dream Book. This is presumably the type of dream interpretation book, based loosely on the ideas of Freud and Jung, which is still popular today.

The Interpretation of Dreams on Book Drum