In the late 1800s, the Parke-Davis pharmaceutical company was basically the biggest weed dealer in America. They promoted their cannabis medicines across the continent, proudly advertising that they rejected literal tons of shwaggy weed each year and used only the dankest primo nugs for their pot products Cannabis' active ingredients were not fully understood at this time. THC and other cannabinoids had not yet been isolated, so there was no way to chemically test extracts for…