Neueste phytochemische Entdeckungen zur Begründung einer wissenschaftlichen Phytochemie. 2 vols.

On pp. 144-146 of vol. 1 Runge reported the isolation of relatively pure caffeine for the first time. He called it "Kaffebase." Digital facsimile from Google Books at this link. In 1821 the French chemists Pierre-Joseph Pelletier and Joseph Bienaimé Caventou independently isolated caffeine without knowledge of Runge's work.