 Morrison & Co. Old Corner Drug Store (the same store where Dr Pepper was first served in 1885) and faded letters on the book's cover spelled out "Castles Formulas".John Castles was a partner of Morrison's for a time and worked at that location as early as 1880.One recipe in the book titled "Dr Peppers Pepsin Bitters" was of particular interest, and some speculated it could be an early recipe for Dr Pepper.