I didn’t find a thread for this, so initiating one under the expectation that it will gradually grow.
This video from the Townsends project is a casual/general exploration of patent medicine—particularly the packaging, marketing, and ingredients—in England and the United States, 17th C–19th C.
Whatever its shortcomings, offers an introductory context for the aromatic bitters and aperitif/digestif bitters of the 19th Century.