title: A letter from Sir James Mackenzie to Dr. Carter Smith, Sr.
mesh_terms: D002309:Cardiology / Q000266:history*; D004501:Education, Medical / Q000266:history*; D004739:England; D006327:Heart Block / Q000266:history*; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans