German chemist (1811-1899) who discovered the elements cesium and rubidium and who developed the laboratory burner that now bears his name. ALS signed “Bunsen,” one page, 4.5 x 5.25, no date. Handwritten letter to a "dear friend," in full: "Will you be so kind to look through the enclosed Introduction to Vol. III before it goes to press?" Bunsen adds a postscript: "I shall send for it to-morrow morning by 10." In very good to fine condition, with trimmed edges, and light wrinkling, and show-through, from old mounting remnants on the back. Bunsen's only published work during his lifetime was Gasometrische Methoden, which was released by Walton and Maberly in 1857.