Journal December 1836
p13–14“Mr D. knows only parts of the Ital n journey and the correspondence with Schiller.”
Fuller, Margaret. "Journal December 1836." Houghton Library, Harvard University; MS Am 1086; Box 3.
Inferred Dana names 'the correspondence with Schiller' explicitly — this is the published Briefwechsel zwischen Schiller und Goethe (1828–29). The Briefwechsel zwischen Schiller und Goethe was published in 6 vols. by Cotta (Stuttgart, 1828–29). It was widely reviewed and read in German literary circles.