Two tiers of materia medica.
Barnby
B
Dun
D000077406:History of Pharmacy; D049672:History, 19th Century; D006801:Humans; D008419:Materia Medica / Q000266:history*; D010595:Pharmacists / Q000266:history; D013782:Textbooks as Topic / Q000266:history*
D008419:Materia Medica