Autograph quotation signed.
Oblong 8vo (postcard). ½ page.
Inscribed to the German dermatologist Alwin Scharlau: "Es ist oft 'ne Kleinigkeit, das des Menschen Herz erfreut [...]".
Accompanying his father, a civil engineer, to Brazil at the age of 15, Keller was able to teach himself drawing by sketching tropical landscapes over a course of five years. He continued his studies at the Karlsruhe Academy upon his return in 1862, advancing to a popular historical painter and portraitist and creating works for prestigious institutions, including the court theatres in Karlsruhe and Dresden.
Traces of postmarks; some small ink spots. Self-addressed by the collector on the reverse. The Mecklenburg physician Scharlau (b. 1888) assembled a collection of artists' autographs by personal application.